351w heads on a 302

[Mac]

Someone used to make head bolts to do exactly what you're asking. I don't recall who. They were 7/16" thread with a 1/2" shank.

ARP makes those head bolts.

 

[Logan95]

They are D5TE. So they’re good heads? Or decent

 

[don4331]

Head bolts from Ford were B2AZ-6065-A (7/16" threads/1/2" shanks). But B2 code starts to date me...

Personally, I like the D1AE-6090-A heads (Aussie Cleveland heads).

 

[Drspencer5]

Pro Comp sells the shoulder washers you need for the 1/2 head bolt holes from the 351 heads to put on a 302.

PCE277.1001

Pardon Our Interruption...

 

[Drspencer5]

What head gasket to use? Intake? Compression issues? Headers?

Your head issue, just use a GT40 or GT40p if you're on a budget. You'll be sorely disappointed with anything less.
If you have no plans for forced induction, a stock replacement gasket will be just fine. Any stock replacement gasket.
Intake must be for a 302. If you're running fuel injection, just use an Explorer intake, if running a carb, a cheap Edelbrock dual plan will be fine. The no name brand ones have a very tight elbow on the front. At least the early ones did.
No cylinder head in your budget will have compression issues
Headers are limited to stock junk or OBX (or Torque Monster).

If you don't have the money right now, you'll save yourself a lot of headache of doing it twice. Just save up for the parts you want so you don't have to dig into it again.

 

[baddad457]

Even the gt40 x/y/p/z etc... heads are all junk. It's not worth wasting the time and effort to swap anything other than an aftermarket head on a sbf.

What a load of CRAP ! Must be a Chevy owner.

 

[baddad457]

You will lose compression as the 351 has a larger combustion chamber, the head bolts for the 351 are larger, 1/2 vs 7/16 for the 302 (as you know) which can cause issues with the heads shifting, making them prone to blowing head gaskets.

The big idea with doing it for "performance" was that the 351 had bigger intake valves and so it could flow better, the problem is that with the mistmatched cylinder and intake port/valve you end up lowering intake velocity, and reducing overall performance.

You are Really misinformed here. It depends on which 351W heads he's going to use. As for the bolt size difference, the cylinder head locating dowels determine where the head sits on the block. The bolts have nothing to do with this. And the so called port mismatch is also BS. The heads would have slightly larger ports, so a slightly smaller intake manifold port dumping into a slightly larger head port is a positive as far as flow goes. Even the other way around was proven long ago to not be a hinderance to flow (bigger intake into a smaller head port) it created turbulence in the flow which enhanced mixing of the air and fuel. (351C 4 bbl intake on a 2bbl head and 429CJ intake on a std 429 head) The chamber volumes are all over the place on the small blocks, so the comp ratio may or may not be reduced.

 

[19Walt93]

If you look up 289/302 cylinder heads on the internet you can find a list of casting numbers with valve sizes and chamber volumes. I'm using the E7TE heads that came on the 95 351 I'm building with only minor porting and the thermactor bumps removed because I want a low rev torque engine. I also have a set of C8OE heads off a 68 302 that have the same size valves and 63cc chambers, screw in rocker studs, and unfortunately rail rockers. Heads that are too big cause low rpm dogginess and a high rpm screamer. Ever drive a 69 Boss 302?

 

[baddad457]

I also have a set of C8OE heads off a 68 302 that have the same size valves and 63cc chambers, screw in rocker studs, and unfortunately rail rockers. Heads that are too big cause low rpm dogginess and a high rpm screamer. Ever drive a 69 Boss 302?

Someone would have had to convert those heads to screw in studs then. As for the rail rockers, that's easily fixed with a set of aftermarket rockers. I've ridden in a 70 Boss and it was no slouch at any rpm.

 

[19Walt93]

I've driven 69 and 70 Boss 30's, 69's had even bigger valves than 70's and were slugs below 2500-3000. 70's were marginally better, that's why they got 3.91 gears with 4.30's optional. They both had about the best stock exhaust sound. If you put in deep enough gears anything will feel snappy. I've rebuilt more heads than I can count, just replacing the rail rockers won't do it, it'll need hardened pushrods a guide plates because the rail rocker was used to center the rocker on the valve stem. In the late 70's I did 1 or 2 valve jobs each week because side stress from the rail rockers wore out the valve guides.
I was surprised to see the screw in studs on non-hipo heads.