Someone asked me if the 351M heads would bolt onto a 302 or 351W. I don't have the answer so I figured I'd ask you guys. Will 351 Cleveland heads bolt onto a 302? Thanks all.

 

First you asked if "M" heads will fit a 302 or a 351W.
Then you asked if 351 Cleveland heads would fit.

Which one is it?

As far as the "M" i dunno, what the hell would you do that for?

The 351C heads will fit on the 302's and Windsors with an adaptor plate. They call the build a "Clevor"

FYI, the 302 Boss heads are very simular to the Cleveland 4V quench heads. I think the only difference was some of the water ports.

 

Yes, all 335-series engine (351C/351M/400) heads will "bolt on" to a 302 or 351W block. The head bolt pattern is the same, and the bore diameter and bore spacing are the same.

They will not work (very long) without modifying the cylinder head water passages to accommodate the wet manifold used on the 302 and 351W. And they require a custom intake manifold to fit the "Cleveland" ports on the 302/351W block.

Why not bolt on a 351M head? It's the same design as the 351C 2V head, and it flows better than any 302 factory head, except the GT40 and GT40P.

 

Apparently KNUCKLEBUSTER you don't know the 335 series that well. The 351M and the 400 both use the 2 barrel version of the 351 4V Cleveland heads. Also, I'm asking this for someone else because I don't know. Duh....

 

What Bubba said is correct. Also there is no "adapter plate" necessary to bolt any 335 series head to a Windsor motor. You will need to get a special intake manifold. You can read more about the 'Clevor' here:

351C heads on a 351W

 

well excuse the hell out of me for tryin' to help

I never claimed to be a 335 "know it all", just repeating some info I've heard through the years.
BTW, I did know it was an adaptor plate for the intake, sorry I didn't make that clear.

 

Actually the adapter plates are only necessary for putting Cleveland manifolds on the 351M/400 motors. All they do is make up for the extra width due to the difference in deck heights.

The 'Clevor' requires a completely new manifold since C/M manifolds are 'dry' and the W is 'wet'.

 

You are probably thinking of the adapter plates that allow you to use a 351C intake manifold on a 351M/400 block. Those adapter plates are required because the taller deck of the 351M/400 block sets the heads farther apart than they are on the 351C block.

Using 335-series cylinder heads on a 302 or 351W requires a custom manifold designed for that purpose because the Cleveland-style ports are located differently on the heads, and their size and shape is completely different than 302/351W ports. Since you're mounting them on the same block, the distance between the heads doesn't change when you use "Cleveland" heads on the 302 or 351W block.

If you've read the posts on this thread, you've learned something too.

Nobody minds when a "non-know-it-all" tries to help, but maybe you came off wrong with the attitude you displayed in your comment:

 

This is an interesting discussion...its the first time I've heard of this special manifold adaptor for the C to M swap. Its good to know they are out there. But I'm guessing the reverse situation could not be accommodated, M to C?

I have a question about the exhaust manifolds, too. Is there any kind of interchangeability between the Cleveland 4bbl exhaust (big ports) and the 2V C and M exhaust (smaller ports) manifolds.

And yet another question...Is this custom designed "Clevor" intake manifold dry? I'm just curious...no plans or anything. What other kinds of changes had to be done to get it to work? (Forget that question, I just went to Bill's link...duh...thanks Bill)

The Boss 302 heads were specifically designed for the "Windsor" 302, hence the name "Boss 302," and were essentially the prototype for the Cleveland style heads. This was supposedly a "Camaro/Mustang" competition type of exercise because Ford was being edged out by GM.

 

I didn't mean that with attitude, maybe I should have used these smilie things next to my comment.

Hope I didn't offend any of our "M" crowd. (foot in mouth)

I visit this site and the different forums "to learn", and share the tid bits I absorb.


Back to the topic.

 

its all good, as long as you learn we are happy. the right answer was given.

 

The Boss 302 was a stop-gap measure to combat Chevy's 302cid Z-28 in Trans-Am racing when the tunnel-port 302's proved unreliable. Engines used had to be production motors and were limited to 5.0L. (Yes, Mopar and Pontiac got a special waivers to use custom destroked 340 and 400 motors.) The heads are basically 351C-4V's with Windsor specific water jacket porting. The special intake to use Cleveland heads on a Windsor is only required for the 302, the 351 is tall enough to use a 351C intake with adapter plates (although a water outlet must still be fabricated). Canted valve crown pistons and special length pushrods are required as well. Boss 302 pistons will not work in a 302 Clevor unless you switch to 289 rods.

 

A company out of Arkansas, B&A Performance, I think, used to manufacture an "adapter" intake, called a Street Boss. This was specifically for 289 / 302's using the 335 head. Both 2V and 4V versions were offered. They also made a manifold for 335 heads on a 351 W. The installation instructions spelled out the necessary changes to the water passages in the heads. They were basic machine shop tasks, nothing exotic. I don't think these manifolds have been made for several years. I just sold a 2V Street Boss intake this past spring. Keep an eye out at swap meets, they do show up every so often. Hor Rod Magazine did an article, called "Bogus Boss", as I remember, many tears ago using one of these manifolds on a 289. The motor had some pretty impressive numbers. Hope this information helps.

 

Hey KnuckleBuster,
we need a head for the 335 Family, casting near the end exhaust valve under the v/cover, D5AE-BA. Have One? Call 405 -227 - 8556 or San Diego bound, 858-560-1957. Thanks for the consideration, Dan

 

Hey BubbaF250,
are still in the flow? We still need a D5AE-BA Head? Any leads? Dan
Call====== 405-227-8556 or 858-560-1957