302 heads on 351m?

[Boggin]

hey guys, im wondering if 302 heads will fit on my 351m? i am pretty sure they will, since the 351c heads fit both the 351m and 302, but most of all, if they heads do fit, will there be any advantages/disadvantages? i have a set of 302 heads that are ported and polished from an 87 5.0 HO and the heads in my 351m have never been off or polished or cleaned up and pretty much every exhaust stud is twisted off in them so they need to come off anyways. so im wondering if these 87 302 heads would work for me. thanks!

 

[adsm08]

Well it would increase compression which would increase power. If it works.

The only problem that I can see that you are likely to encounter is head bolts. I know on the Windsor engines the 351 head bolts are bigger around than the 302 bolts. I don't know if that carries over to the M block or not, but I would guess it does. My suggestion would be to spend the $2 to get a head bolt and see if it fits through the hole in the 302 head.

 

[Boggin]

Are regular grade 8 bolts good enough for the heads or do it have to be head bolts?

 

[shane96ranger]

I've heard of Cleveland heads on a Windsor, but not the reverse. Maybe you can use this article to help you get there.

http://www.darkhorseracing.net/clevor_head_mod.htm

 

[v-8power]

You should post this question in the v8 forum. The 351M is a different monster compared to the windsor block engines.

 

[Boggin]

i know the engines are different. just wondering if it could work, and never though of posting it there at that time

 

[stevealvey24]

Theres a couple things that are different if I'm remembering right. First you will have to drill the heads for 1/2" bolts as 302's are 7/16". Also if I remember right the intake is a different bolt pattern and I'd say theres not an intake available to fit the large width of the 351/400 block.

 

[pjtoledo]

and something about water passages at the front of the heads. welding holes on one surface and making new holes on the other surface. I'd check the compression ratio and chamber size on both heads as there may be nothing to gain.

 

[brinker88]

If it were a windsor, yea...not really sure about the M