Rebuilt 302 casting heads available through Rockauto

[George Jets]

So if I have a stock 67 273 and I put these heads on, approximately what would the final compression ratio be?

It depends how high your pistons are sitting in the hole at Top Dead Center. The prefered 69 318 factory valve relief pistons sit .045 ths down in the hole, this is about the best stock piston you can get for the 318s but are in short supply. With the 302 heads and the thinner smaller diameter head gasket you run real close to 9.5:1 compression ratio as an example.

Next best piston choice for the 318 is the 93 Ram Truck 318 flat top piston they probably sit .070 down in the hole but don't have the valve reliefs so that helps compression some too. Around 9:1 give or take.

Think the 67 273 probably had pretty good compression for back in the day, so the 302 heads should help them a lot. ToolManMike did a 273 build with the original 67 Closed Chamber heads, might want to see if you have these heads already on your engine. ToolManMike would be good for more info if you need it too.

The new Reman heads: 302, 646, and 714 castings are all the same head. Better Ports and Port Flow than earlier 318 factory heads.

69 318 Factory 230 hp engine, 340 camshaft, 302 heads.

Have fun with your 273 . . .

 

[George Jets]

Pardon my ignorance, what makes this head desirable

Closed Chamber increases compression ratio, making more power and better fuel efficiency. Better port sizing and port flow design as compared to the early 318s.

Just makes more power . . .

 

[toolmanmike]

So if I have a stock 67 273 and I put these heads on, approximately what would the final compression ratio be?

About the same. 273 heads have similar sized chambers.

 

[rumblefish360]

There biggest claim to fame is when Ma MoPar used the 302 head in there performance catalog when they dyno’d there 302 head, the fully ported version made 55 HP over the then go to 360 head.

 

[toolmanmike]

Something to remember guys, ANy 318 LA head after 1967 is a open chambered head. The closed chamber adds efficiency and compression.

 

[nm9stheham]

So if I have a stock 67 273 and I put these heads on, approximately what would the final compression ratio be?

If this is a 2 BBL engine, the final static CR with these heads will be about 8.5 to 8.6. If this is a 4 BBL, then I'll guess around 9.5. (The dome volume above deck with the 4 BBL pistons is a bit murky to me.... IIRC TMM has come up with some of the numbers.)

 

[Richard Sweet]

Well, I ordered 2 Famous Brand 2D31 rebuilt heads from Rock Auto yesterday. It was a 4 hour, on line ordeal with customer service. I won't get a warranty because my '65 273 Dodge A100 van is not on their list of qualified vehicles and their system requires a 17 digit vin #; my vehicle only has 10 digits. The costs were: $417.58 for the heads (including $100 for cores) + $39.98 for the cheapest FedEx ground shipping + $35.46 CA tax = $493.02. I should get them in about a week. I don't know when they will do another run.
This is a good thread.
Thanks FABO, Richard

 

[toolmanmike]

Well, I ordered 2 Famous Brand 2D31 rebuilt heads from Rock Auto yesterday. It was a 4 hour, on line ordeal with customer service. I won't get a warranty because my '65 273 Dodge A100 van is not on their list of qualified vehicles and their system requires a 17 digit vin #; my vehicle only has 10 digits. The costs were: $417.58 for the heads (including $100 for cores) + $39.98 for the cheapest FedEx ground shipping + $35.46 CA tax = $493.02. I should get them in about a week. I don't know when they will do another run.
This is a good thread.
Thanks FABO, Richard

Hope all goes well. Post some photos when you get them.

 

[toolmanmike]

I was thinking pretty serious about pulling the trigger on those but I am a ways away from doing anything to my 318. I have a pair of 302's in the garage that need rebuilt. I know it will cost me more than the ones you bought.

 

[Richard Sweet]

I was thinking pretty serious about pulling the trigger on those but I am a ways away from doing anything to my 318. I have a pair of 302's in the garage that need rebuilt. I know it will cost me more than the ones you bought.

Mike,
You've got 2 cores worth $100 to Rock Auto, when they get more in. Do you want to work on your own heads? You could still take their rebuilt ones apart to port them or whatever.

 

[toolmanmike]

Mike,
You've got 2 cores worth $100 to Rock Auto, when they get more in. Do you want to work on your own heads? You could still take their rebuilt ones apart to port them or whatever.

I haven't taken mine apart but I bet they could use some valves. They came out of a good running 5th. Avenue but it had 100,000 rounds on it and not well cared for. Teen heads work well with larger valves and with different guides you can use Magnum valves. (smaller stems) I would have Woody port them like he did my 273 heads.

 

[George Jets]

Well, I ordered 2 Famous Brand 2D31 rebuilt heads from Rock Auto yesterday. It was a 4 hour, on line ordeal with customer service. I won't get a warranty because my '65 273 Dodge A100 van is not on their list of qualified vehicles and their system requires a 17 digit vin #; my vehicle only has 10 digits. The costs were: $417.58 for the heads (including $100 for cores) + $39.98 for the cheapest FedEx ground shipping + $35.46 CA tax = $493.02. I should get them in about a week. I don't know when they will do another run.
This is a good thread.
Thanks FABO, Richard

OK Richard
I was wondering who the lucky FABO memder was that got that first set of heads that just came through, now I know. Lol . .

I found a work-around for the vehicle serial numbers they ask for as all the mopar builds are usually a custom built engine not current with today's vehicle VINs.

When asking for the VIN the order would not go through, so I just put all Zeros for the VIN and then the order went through. Can try all Ones also. I imagine this is where your 4 hour deal came in.

Should just take 15 minutes using the zeros and then you can check out.

Hope this helps others when ordering when they get restocked again. I got the 1 year warranty too using the online order and not going through customer service.

The heads have heat tabs on them, so as long as you don't overheat them and melt the heat tab off the 1 year warranty is good.

George Jets

 

[Dana67Dart]

Something to remember guys, ANy 318 LA head after 1967 is a open chambered head. The closed chamber adds efficiency and compression

So what you are saying is that a 273 engine built 12-66 would have closed chamber heads so these heads would not raise the compression ratio?

 

[Richard Sweet]

George,
Where are the heat tabs and what do they look like?
I've heard that the 302 exhaust seats were induction hardened on the stock engines. Are they just reground on a valve job or are new hardened seats pressed in on the Famous Brand reman?
How can one tell?

 

[George Jets]

You can see the silver button on the front head frost plug for the heat temp tab.

Believe they are the induction hardened, stays pretty good, think they put new valves with 3 angle grind to them. Probably just a minor lap to lap them in.

 

[toolmanmike]

You can see the silver button on the front head frost plug for the heat temp tab.

Believe they are the induction hardened, stays pretty good, think they put new valves with 3 angle grind to them. Probably just a minor lap to lap them in.

View attachment 1715393923

Yep, those heat tabs are there for warranty. If you overheat and warp or crack a head, no warranty.

 

[George Jets]

You can see the silver button on the front head frost plug for the heat temp tab.

Believe they are the induction hardened, stays pretty good, think they put new valves with 3 angle grind to them. Probably just a minor lap to lap them in.

View attachment 1715393923

Yes induction hardened seats, just double checked a new reman set from Rock and I have a take off set pictured here with 60,000 miles on them. Exhaust seats are standing up real nice, hardened not wearing away and sinking the valves like the non hardened valve seat heads do.

 

[Wyrmrider]

good to know george

 

[toolmanmike]

So what you are saying is that a 273 engine built 12-66 would have closed chamber heads so these heads would not raise the compression ratio?

No the 67's are closed chambered. The 68 and newer 273/318 heads are open chamber.

 

[Richard Sweet]

Mike,
I think you should qualify your statement; except the newer than '68: 302, 646 & 714 heads which have closed chambers, right?

 

[Richard Sweet]

George,
What temp do those buttons on the freeze plugs on the heads melt at?

 

[George Jets]

George,
What temp do those buttons on the freeze plugs on the heads melt at?

- Provides visual evidence of Overheating

- Melting Point of center material is approximately 260F (127C)

 

[toolmanmike]

Mike,
I think you should qualify your statement; except the newer than '68: 302, 646 & 714 heads which have closed chambers, right?

I have a list but no time to post. On my phone and heading for church.

 

[Richard Sweet]

That location is close to the 2 front exhaust ports, so I guess that's a pretty good place to monitor temps. Prestone says that a 50% mixture protects against boil over to 265*F.

 

[George Jets]

It is crazy, I don't like headers at all. Way more engine bay heat, noise in the engine compartment transferring to the interior of the car. Not to mention what a pain they are to put on and work around, always in the way for everything.

We are doing the street cars here. Back when I was a kid a guy put headers on his Roadrunner, it slowed his car down so he put the stock manifolds back on and he was good to go again.

I am sure there are plenty of people that love the headers for various reasons. My thinking to avoid the headers is to let the hot compressed exhaust gasses come out of the heads and through the manifolds, (where they are still compressed yet). Then dump those hot exhaust gasses into a 2 1/2 inch exhaust system all the way to the back of the car. The hot gasses are expanding the full length of the exhaust system creating a suction to help pull spent gasses out of the engine.

Just my thinking here, others will differ for sure. We have an exhaust system here on the 318 302 Heads with stock manifolds, that what can I say, just flat out performs. You can make up you own mind on how you would like to do things.

Just like the flame of this rocket expanding it's exhaust gasses after they leave the main rocket engine. The expanding flame pretty much dwarfs the size of the rocket it'self.

However you want to build your projects is fine with me. It's all pretty specific for your desired outcome and how the car is going to be used in the end.

Happy Motoring . . .