How to identify "302" heads???

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str12-340

str12-340

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Just like it says, I'm buying a 318 that is said to have 302 heads. How can I be sure that they really are? Is 302 the last 3 numbers of the casting number (which I think would be found under the valve covers along a port runner)?

Thanks for the help!
 
str12-340 said:
Just like it says, I'm buying a 318 that is said to have 302 heads. How can I be sure that they really are? Is 302 the last 3 numbers of the casting number (which I think would be found under the valve covers along a port runner)?

Thanks for the help!
Click to expand...
Yes
 
str12-340 said:
Just like it says, I'm buying a 318 that is said to have 302 heads. How can I be sure that they really are? Is 302 the last 3 numbers of the casting number (which I think would be found under the valve covers along a port runner)?

Thanks for the help!
Click to expand...

Yes,

302 Castings 005.JPG


302 Castings 013.JPG
 
str12-340 said:
Just like it says, I'm buying a 318 that is said to have 302 heads. How can I be sure that they really are? Is 302 the last 3 numbers of the casting number (which I think would be found under the valve covers along a port runner)?

Thanks for the help!
Click to expand...
What year is the teen?
 
'86 to '91 318 TBI Roller engines came factory with 302 heads.

714 casting is the exact same heads, just a different number.

1020161036.jpg
 
The last really high compression year for 318 was 1969. After that it decreased with each
year.
 
toolmanmike said:
Those are pretty George. Nice score!
Click to expand...

Thanks, got them here sitting on the shelf ready to go. Got them back when they were in stock at Rockauto. Was thinking I better get a set while I can.

Sure enough they went out of stock and that was the end of the supply.
 
George Jets said:
714 casting is the exact same heads, just a different number.
Click to expand...
Thanks for everybody's quick response! Question for George Jets: On the 714 heads is that casting number under the valve cover as well as on the Combustion chamber side? The engine is assembled as a long block, so it would be easier to see that way.
 
Treblig said:
The last really high compression year for 318 was 1969. After that it decreased with each
year.
Click to expand...
is it true that given the same short block, these closed chamber heads will bump up compression a bit?
 
str12-340 said:
is it true that given the same short block, these closed chamber heads will bump up compression a bit?
Click to expand...

Yes, smaller closed chamber vs open chambers. Larger push rod holes too so the push rods don't rub the head.

Want even more compression, thin .028 ths Head Gaskets by Mr Gasket are available. # 1121G
 
These reman 302 / 714 closed chamber heads have also been milled to clean up the gasket sealing surfaces.

1020161100.jpg


Probably .010 ths milled off for clean up, every little bit helps on getting more compression.

Port matching the 302 heads to the Felpro 1243 intake gaskets helps a lot for the port flow into the heads also. Smooth port flow on the 318s is what you want.

20200626_145510.jpg
 
str12-340 said:
Thanks for everybody's quick response! Question for George Jets: On the 714 heads is that casting number under the valve cover as well as on the Combustion chamber side? The engine is assembled as a long block, so it would be easier to see that way.
Click to expand...

Yes, whether 302, 646, 714 all the same heads, last 3 digits will be there under the valve cover.

20200816_165923.jpg
 
great buy
use the mr gasket (guessing lowcompression 318)
cc the heads
post up your measured compression numbers
 
Wyrmrider said:
great buy
use the mr gasket (guessing lowcompression 318)
cc the heads
post up your measured compression numbers
Click to expand...

9.2:1 cr stock 318 with flat top pistons
.040 ths down in the hole.
(1968-69 stock 318 valve relief pistons).
Factory 230 hp engine

9.2:1 cr Stock 1991 318 Roller Engine
Factory 230 hp
Flat top pistons with no valve reliefs.
Same .040 ths down in the hole, so these will give a bit more compression than the 68-69 valve relief pistons.

Mr. Gasket Head Gaskets 1121G
.028 ths compressed thickness.
vs Felpro .035 ths head gaskets.

302 Closed Chamber Heads gains 1/2 a point on compression ratio, over stock open chambers.
302 heads are like 65cc

9.2:1 stock 318 short block
.5 302 closed chamber heads
.1 thin head gaskets
_______
9.8 : 1 cr

Reman heads were milled .010 ths for clean up, so you can figure that in there too.
3 angle valve job, with new valves so the valves are standing up high too.

Port Matching heads to intake gasket required too.

I don't claim to be a full blown machinist.
So this is what we got for now.

Just to keep it simple we call it a 9.5:1 cr.

1020161100.jpg


318 3.jpg


318 6.jpg


IMG952017011295175305873.jpg
 
Last edited:
Also the Mr Gasket 1121G thin head gaskets are kind of a double win.

They are not only thinner when compressed down, but they fit the 318 bore better too. Made specific for the 318.

The Felpro replacements are universal 318/360 head gaskets, which are actually just 360 head gaskets that they use on the 318s.

So you end up with a larger diameter gasket when used on a 318 leaving you with a little less compression on your engine build.

It all adds up . . .
 
so 256-260 @.006 cam is going to give you what Aj/form s talks about for street
see the list I just posted i the 318 cam stickie
 
Wyrmrider said:
so 256-260 @.006 cam is going to give you what Aj/form s talks about for street
see the list I just posted i the 318 cam stickie
Click to expand...

Like the guy was saying, all those numbers and his head is spinng.

Wyrmrider you obviously have huge experience. But for the rest of us laymen I need simple proven grind numbers like Ma Mopar's 340 cam as my baseline.

Just like the way they run, seen too many people with too much cam end up with a new engine not running very good because of cam selection.

Just want something that works nice so I can get on to everything else that needs to be done and not worry about the wrong cam. Not racing here, thanks.

Have lots of hands on experience with different cams on different engine formats, not just the V8s, still like to keep it simple.

I am a big fan of Ma Mopar getting it right back in the day. I like their lift and set down ramps on the cam lobes. For sure other cams are available . . .
 
Ma mopar got it right for Emissions but the 68 and later 340 cam is a smog cam masqueradig as a performance cam
closing exhaust late to give an egr effect with exhaust dilluting the intake charge- who needs that
you have to unnecessairly rev it up to clean up the charge
opening the exhaust early- see aj's posts in Jeffery's thread concurrent with this one - expansion ratio
and advancing it makes worse on the efficiency side
Hughes stroker cam recommendation
closing the intake late even late for a stock real 9.5:1 340 and really really late for a 360 or late 318
DCR goes all to hell
who needs the really long ramps especially the uper long closing ramps
good points KISS
now if you blueprint to a true 10.+ CR and run low gears I've raced it there when we had to iven with the crap 68> heads
 
How much power you looking for ?
stock 318 heads are good for about 300 hp.

If you built a pocket ported 302 heads with 9.5:1 cr with quench be nice and a something like a comp xe268h-xe275h cam might do a 323 cid @ 323 hp engine, If you want more than that you need better heads and or more cam & CR. Personally I'd go with at least Magnum or even 360LA heads if you added cr with pistons.
 
So, originally I was just looking to confirm the heads I'm told are on an engine that I'm buying for a 70 Dart GT I'm building are 302 swirl port heads. Since this has gone waaaay past that - and I've really enjoyed all the information that has been shared - I should answer 273's question - I'm building a car to use for looong distance road trips - like on the road for months at a time, going from coast to coast and back. Rt 66 kind of driving. The car needs some get up and go, especially in the bottom end, it might never see more than 5000-5500 rpm and it can't break the bank on gas. I'm currently thinking of using a Silver Sport automatic that has very low 1st gear, wide ratio spacing and a really high overdrive 4th gear. As compare to a TQ, with 3.73 gears it should have 1st like 4.30 gears and 4th like 2.70 (something) gears.
 
2.94 gears are great gears for cruising and freeway speeds of today.

Had them in the '69 Satellite, stock 318 with 4 bbl, 727 trans. Good low end torque engine and can still pass anyone you want on the freeway.

Favorite Gearing, pulled around the B Body just fine, at 20 miles per gallon too.

Screenshot_20200803-230319_Gallery.jpg
 
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