Help identifying pistons and cylinder heads

[mshred]

Have this 360 torn down and have a few questions.

Wondering if the pistons are stock, or stock replacements at .030 over. I ask because they all have the stamping "30" on them as pictured. I didnt get a chance to clean up the carbon in the cylinders, but managed to get a 4.02 reading on the one cylinder I measured with cheap digital calipers digging into a good layer of carbon at the top. Could these very well be replacements? They are over .100" in the hole still.

The cylinder heads are definitely small valve 1.88/1.60 heads, but im wondering what heads they are- none of the numbers on them seem to be numbers ive ever seen i.e. 596, 308, 302, etc. Based on the attached pictures, what do you guys make them out to be? I ask so I can look up info on them i.e. possible porting templates or flow

Last but not least, wondering if the valve spring and retainer appear factory? This engine has a very mild cam in it from what I am told, and how it sounded, but I haven't gotten the balancer off yet to get the timing cover and cam out. Wondering if the picture is telling as to whether they appear to be factory or aftermarket valvetrain parts.

Thanks!

 

[66signet]

https://www.mopar1.us/headcastnumber.html
This shows the heads to be 83-86 police heads with 1.78 intake and 1.60 exhaust valves . I don't know the difference between police heads and other LA heads of those years.piston may have other numbers or markings on the bottom that may help identify them.

 

[Hellrats]

They look like .030 over stock replacement pistons to me

 

[Syleng1]

I second .030” over stockeroos.

The heads easy enough to look into.

 

[mshred]

https://www.mopar1.us/headcastnumber.html
This shows the heads to be 83-86 police heads with 1.78 intake and 1.60 exhaust valves . I don't know the difference between police heads and other LA heads of those years.piston may have other numbers or markings on the bottom that may help identify them.

I took a set of calipers to the valves this morning and you are right, the intake is 1.78...yikes...not even 1.88

They look like .030 over stock replacement pistons to me

I second .030” over stockeroos.

The heads easy enough to look into.

Yea I can't imagine the 30 stamped in them being for anything else, but figured I would ask in case others have the same pistons in an engine of their own and can confirm that indeed that stamping suggests .030" over.

 

[rumblefish360]

Look under the head, valve side pictured below you’ll find some numbers. The air injection ports, the small holes under the exhaust ports point to a smog gear head. IIRC, they started that in the later ‘70’s. I’ve seen them plugged with JB Weld, aluminum foil, but the best way to seal them up is tap to a 1/4-20 and use Allen head studs sitting below the surface and with red loctite to keep them there.

The head will port out reasonably well. Accept the next valve size up EZ. If it’s a 1/88/1.60 head, you can go 2.02 no problem.

 

[rumblefish360]

While I was typing, you posted.

1.78 valves = 318 heads. That 360 ran out of breath quicker with this heads. Probably capable of high torque and mileage though.

Installing a 2.02 and porting the bowl area to take advantage of the bigger valve is a crap ton of work. I’d leave that alone and seek a different head.

How is the bottom end?

 

[mshred]

While I was typing, you posted.

1.78 valves = 318 heads. That 360 ran out of breath quicker with this heads. Probably capable of high torque and mileage though.

Installing a 2.02 and porting the bowl area to take advantage of the bigger valve is a crap ton of work. I’d leave that alone and seek a different head.

How is the bottom end?

Yea, it looks like im either going to try and find a set of nice irons locally for a fair price, or maybe cough up for a black friday special set on the speedmaster site in a couple of days. Realllllly was not wanting to spend that kind money though, and as you said, its not worth the money/effort to get these heads up to snuff for me...kinda annoyed, already killing the budget it seems now having to figure out another option for heads, but this just may be why this thing was so gutless in a heavy car lol

Bottom end looks okay. I tore this down last night very late in the garage, as getting the time is hard for me these days, so I really didn't do a close inspection. I will try to get out tonight, but on quick glance the cylinders do look good, just a bit of carbon up at the top that I removed with a finger nail on one cylinder and found no ridge.

 

[pittsburghracer]

Yea, it looks like im either going to try and find a set of nice irons locally for a fair price, or maybe cough up for a black friday special set on the speedmaster site in a couple of days. Realllllly was not wanting to spend that kind money though, and as you said, its not worth the money/effort to get these heads up to snuff for me...kinda annoyed, already killing the budget it seems now having to figure out another option for heads, but this just may be why this thing was so gutless in a heavy car lol

Bottom end looks okay. I tore this down last night very late in the garage, as getting the time is hard for me these days, so I really didn't do a close inspection. I will try to get out tonight, but on quick glance the cylinders do look good, just a bit of carbon up at the top that I removed with a finger nail on one cylinder and found no ridge.

One of our members bought a set of cast iron heads from Speedmaster. He wasn’t real pleased with the flow numbers but for the price I’m betting they are way better than what you have. Maybe they will add more info if they see this.

 

[PRH]

Did you measure the valve sizes yourself?
Are the intake port openings the 360 or 318 size?(in the pic, the exhaust port openings appear to be 318 sized to me)

Pretty much any new iron head you can buy now will be a magnum based head.

It’s not that big of a job to recut 1.78/1.50 seats for 1.88/1.60 valves.
(For me, I would only consider this if the heads have 360 sized intake ports. If they’re 318 sized ports, I’d look for some castings with 360 sized ports)
But depending on the overall condition of the heads, it’s possible to end up with a bigger bill reconditioning your(or other) old heads than many people think.
That will likely come down to what machine shop labor costs in your area are.

 

[mshred]

One of our members bought a set of cast iron heads from Speedmaster. He wasn’t real pleased with the flow numbers but for the price I’m betting they are way better than what you have. Maybe they will add more info if they see this.

Oh, if I go with aftermarket heads it will be aluminum. I think from what I looked at before, it would be like $700 for a set of the speedmaster aluminums setup for flat tappet (for the pair). I will only stay iron if I can find a cheaper set locally.

Did you measure the valve sizes yourself?
Are the intake port openings the 360 or 318 size?(in the pic, the exhaust port openings appear to be 318 sized to me)

Pretty much any new iron head you can buy now will be a magnum based head.

It’s not that big of a job to recut 1.78/1.50 seats for 1.88/1.60 valves.
(For me, I would only consider this if the heads have 360 sized intake ports. If they’re 318 sized ports, I’d look for some castings with 360 sized ports)
But depending on the overall condition of the heads, it’s possible to end up with a bigger bill reconditioning your old heads than many people think.
That will likely come down to what machine shop labor costs in your area are.

I think I mentioned it above, but I went out to the garage quick this morning to measure the valves, and they are indeed the 1.78/1.60.

The only iron heads I would purchase would be if I could find a reasonably priced factory casting with larger valves in them already. Otherwise I will look at aluminum aftermarket. Machine shop costs here are not cheap, so reworking factory heads is really not something in the budget unless I would be building a stock eliminator type deal where I had to use them.

 

[pittsburghracer]

Oh, if I go with aftermarket heads it will be aluminum. I think from what I looked at before, it would be like $700 for a set of the speedmaster aluminums setup for flat tappet (for the pair). I will only stay iron if I can find a cheaper set locally.

I think I mentioned it above, but I went out to the garage quick this morning to measure the valves, and they are indeed the 1.78/1.60.

The only iron heads I would purchase would be if I could find a reasonably priced factory casting with larger valves in them already. Otherwise I will look at aluminum aftermarket. Machine shop costs here are not cheap, so reworking factory heads is really not something in the budget unless I would be building a stock eliminator type deal where I had to use them.

If you go with this set that are set up for hydraulic roller the come with nice 10 degree retainers and keepers. The springs are reportedly set up light for a 600
Lift cam which plays into the hands of many guys wanting to run smaller lift cams. If I remember right there were 4-6 shims to even lower the pressure more. The retainers were chrome moly and very nice looking. If the sale happens these were 40% off this price shipped free.

 

[mshred]

If you go with this set that are set up for hydraulic roller the come with nice 10 degree retainers and keepers. The springs are reportedly set up light for a 600
Lift cam which plays into the hands of many guys wanting to run smaller lift cams. If I remember right there were 4-6 shims to even lower the pressure more. The retainers were chrome moly and very nice looking. If the sale happens these were 40% off this price shipped free.

View attachment 1716169461

Thank you for the info! Maybe if I go for these ones, instead of the hydraulic flat tappet ones, I can run a solid flat tappet instead...but then I will have to spring for some adjustable rockers, as I don't think the factory stamped obviously can be used....Im just watching the budget fly out the window as I think right now! lol

They are a damn good deal on Black Friday though for sure. Would you be confident running these heads out of the box John?

EDIT: I see the valve springs are listed as 145 closed and 360 open for the hydraulic flat tappet. Wonder if that's enough for some solid flat tappet cams.

 

[pittsburghracer]

Thank you for the info! Maybe if I go for these ones, instead of the hydraulic flat tappet ones, I can run a solid flat tappet instead...but then I will have to spring for some adjustable rockers, as I don't think the factory stamped obviously can be used....Im just watching the budget fly out the window as I think right now! lol

They are a damn good deal on Black Friday though for sure. Would you be confident running these heads out of the box John?

The guides are looser than Edelbrock guides which I prefer. I found one very loose guide (.003 over) and the chambers weren’t finished on the same set. These were bare heads and probably would have hopefully been caught if they were assembled. This was out of about 15 sets. I don’t recommend running even the best heads out of the box as they should be taken apart, inspected, and cleaned. They have a very nice looking set of upgraded 1.5 rockers that I had in my cart several times.

 

[mshred]

The guides are looser than Edelbrock guides which I prefer. I found one very loose guide (.003 over) and the chambers weren’t finished on the same set. These were bare heads and probably would have hopefully been caught if they were assembled. This was out of about 15 sets. I don’t recommend running even the best heads out of the box as they should be taken apart, inspected, and cleaned. They have a very nice looking set of upgraded 1.5 rockers that I had in my cart several times.

Yes, for sure, but I guess Im just meaning will they hopefully need little to no work. Sounds like overall they have been good in your experience.

And yes, they call them the "DNA rockers". Have you used the other ones they sell that are blue and red? Wondering how they hold up, as I know the china rockers years ago were a BIG no no due to quality of materials used and bearing style.

 

[pittsburghracer]

Yes, for sure, but I guess Im just meaning will they hopefully need little to no work. Sounds like overall they have been good in your experience.

And yes, they call them the "DNA rockers". Have you used the other ones they sell that are blue and red? Wondering how they hold up, as I know the china rockers years ago were a BIG no no due to quality of materials used and bearing style.

I only run T&D rockers or mostly Harland Sharps but I’ve heard bad stories about the cheaper blue and red rockers. I do like the looks of the DNA ones and at 40% off were hard to pass up. I grabbed a set of their heads studs but never needed them so far. The rocker shaft spacers are very cheap too.

 

[rumblefish360]

Possibly Mancini racings rockers are in the budget. There made for Mancini by Harlandsharp.

 

[Dartswinger70]

Did somebody put tree eighteen heads on a three sixty...?

 

[rumblefish360]

Yup!!!!

 

[Dartswinger70]

Yup!!!!

It makes me wonder and I tend to over think, but was it that they needed heads and thats all they had, or did they think they were "upping compression" and didnt know bout the ports and the smaller runners or did they even care I suppose it doesnt matter but I had someone on the interwebz tell me to "put 318 heads " on my 340 because it will "raise the compression" and I always wondered if they were serious or...

 

[mshred]

It makes me wonder and I tend to over think, but was it that they needed heads and thats all they had, or did they think they were "upping compression" and didnt know bout the ports and the smaller runners or did they even care I suppose it doesnt matter but I had someone on the interwebz tell me to "put 318 heads " on my 340 because it will "raise the compression" and I always wondered if they were serious or...

Just to clarify, it was not me who assembled this motor like this...I would have never done such an idiotic thing lol. I can understand the port velocity thing to an extent, but a 360ci engine needs to breathe, regardless how "mild" it may be. That's just my opinion.

 

[Hellrats]

Good heads can make any engine come alive... Bad heads can kill it

 

[rumblefish360]

It makes me wonder and I tend to over think, but was it that they needed heads and thats all they had, or did they think they were "upping compression" and didnt know bout the ports and the smaller runners or did they even care I suppose it doesnt matter but I had someone on the interwebz tell me to "put 318 heads " on my 340 because it will "raise the compression" and I always wondered if they were serious or...

Yes, by putting the teen heads on the 340/360, yes, compression will rise. Break out the calculators and dial indicators, cc those chambers!!!!
The problem here is the smaller ports will restrict breathing at a lower rpm than the correct oem heads would. How much I don’t know.

As @mshred had said in early posts…..

The increased compression is a plus on one hand, the small valves and port size are the flip side. A big minus. The thinking, *I Think!* is an attempt to increase the efficiency with the smaller chamber, valve size and comp ratio. It’s a solid thought IF you’re attempting more mileage.

Now the heads are stock and the valves are small. Installing the 360’s 1.88/1/60 valves and porting the head out to its best potential would yield a minor increase in terms of flow. Obviously I think (danger!) none of us would travel this route since the port can’t be made big enough to feed a decent street performing 340/360. Though the head would still be OK for very mild camshafts and acco. gear. On a 318, it would be a very good street head.

Maybe so, the previous owner just used what he had in hand. Said screw it, it is what it is and away it goes.

IF Maurer can find decent, cheap and local OEM heads, that would be really good. New aluminum is just expensive for a cheap build but better suited on a stock 340 over the oem head. Very good on an upgraded 360 even if it’s still a low compression engine. He can run pump camel pea 87 octane without issue with even a really nice upgrades camshaft. Like he has in thought now.

 

[Hellrats]

In a truck or a cruiser with a small cam who cares. It will run good and you don't need high RPM anyway.

 

[mshred]

Yes, by putting the teen heads on the 340/360, yes, compression will rise. Break out the calculators and dial indicators, cc those chambers!!!!
The problem here is the smaller ports will restrict breathing at a lower rpm than the correct oem heads would. How much I don’t know.

As @mshred had said in early posts…..

The increased compression is a plus on one hand, the small valves and port size are the flip side. A big minus. The thinking, *I Think!* is an attempt to increase the efficiency with the smaller chamber, valve size and comp ratio. It’s a solid thought IF you’re attempting more mileage.

Now the heads are stock and the valves are small. Installing the 360’s 1.88/1/60 valves and porting the head out to its best potential would yield a minor increase in terms of flow. Obviously I think (danger!) none of us would travel this route since the port can’t be made big enough to feed a decent street performing 340/360. Though the head would still be OK for very mild camshafts and acco. gear. On a 318, it would be a very good street head.

Maybe so, the previous owner just used what he had in hand. Said screw it, it is what it is and away it goes.

IF Maurer can find decent, cheap and local OEM heads, that would be really good. New aluminum is just expensive for a cheap build but better suited on a stock 340 over the oem head. Very good on an upgraded 360 even if it’s still a low compression engine. He can run pump camel pea 87 octane without issue with even a really nice upgrades camshaft. Like he has in thought now.

Exactly! We will see how creaky my wallet is feeling tomorrow and if I can find anything locally used today.

In a truck or a cruiser with a small cam who cares. It will run good and you don't need high RPM anyway.

My idea of "cruiser" and "small cam" are probably a lot different then most people on here, I have come to realize...RPM is important to me.

On another note, Happy Thanksgiving all!