I have a 81-86 302 short block and i want to stick 351 heads on it to get that extra flow. what all is required to make this happen and how difficult is it? and lastly is it even worth it?:SNSign:
351 heads on a 302
- Thread starter bad68coupe
- Start date
LMan
Founding Member
tos
Founding Member
I'm assuming you are talking about windsor heads? Anyway if they are windsors they will fit with no mods as long as you use a 289 or 302 intake you'll be fine. However if they are 351w heads built after 77 then I would just use 289/302 small chamber heads cause after 77 they were low compression low performance design with small ports and huge combustion chambers. Go with early 351 heads for the best improvement or 289/302 and have them ported with larger 2.00/1.6 valves and gasket matched porting. The other alternative which is also good are aftermarket heads. Also I think some of these later 302 engines might have dished pistons? Maybe i'm wrong about that but if yours does you'll want to get rid of those.
PS 351 cleveland heads wont work.
PS 351 cleveland heads wont work.
1320stang
Founding Member
It's said you'll need some different stepped headbolts or stepped washers as the 351w diameter is bigger than the 289/302 size. I believe all aftermarket heads have the 351w sized holes as well. That being said, I ran '69 351w heads on a 289 without the stepped bolts of washers just fine.
The Cleveland heads will work, but you have to perform some water port modifications and run a special intake. B&A used to make the intake, but I think they're out of business now, although I think someone else was making them now, they had two intakes, a StreetBoss and a TrackBoss intake.
The Cleveland heads will work, but you have to perform some water port modifications and run a special intake. B&A used to make the intake, but I think they're out of business now, although I think someone else was making them now, they had two intakes, a StreetBoss and a TrackBoss intake.
tos
Founding Member
1320stang said:
This is true but the reason I said they would not work is there is far to many things to change/modify to make it worth your while. There is alot more to consider than what is listed here. Cleveland heads are like boss 302 heads and have stagered valves. You would need to use boss or cleveland style pistons which also would require different length rods because the boss and cleveland pistons (stock ones anyway) have a different wrist pin location (pin Height). Rocker arms are different ratios (boss and cleveland are 1.73 and 302 are 1.6). I'm not sure but I think even exhaust manifold mount is different. There are just too many things to make them work when there are much better options available. If you just want a little bit more power and are not going to do other radical mods then I would port and polish stock heads and go with bigger valves or slap on some windsor heads
1320stang
Founding Member
We're not saying it's not expensive, but the Cleveland style heads will make more power than a Windsor style head. Nascar uses them, the Outlaw guys use them. If you want to make a lot of power, they certainly are worth your while. I agree, for 90% of the people out there, a Windsor style head is fine and I'll go further than that and say that for 80% of those people, modified iron heads are fine as well. I was just taking exception to your blanket statement that 351C style heads would not work on a 289/302/351W. You never know what newbie might read that and not know any better. He might get on another board where someone is talking about putting some C heads on a W and he'll tell them you can't and that TOS on StangNet said so. They'll tell him that TOS is a D/A as probably everyone else on StangNet. Can't have that.
tos
Founding Member
Damn I hope they dont stoop so low as to call me a D/A. That would really piss me off
Maybe I should'nt have said "they wont work". lots of things can be made to work in situations they were'nt meant for.
I'm not contradicting anything anyone said I'm just adding information cause I believe if I say something will work then I'm obligated to Tell them everthing they have to do to make it work. On the same token he could go to another stang forum and say so and so said just use this intake and modify the water ports and you can use c heads. Cant have that.
Maybe I should'nt have said "they wont work". lots of things can be made to work in situations they were'nt meant for.
I'm not contradicting anything anyone said I'm just adding information cause I believe if I say something will work then I'm obligated to Tell them everthing they have to do to make it work. On the same token he could go to another stang forum and say so and so said just use this intake and modify the water ports and you can use c heads. Cant have that.
1320stang
Founding Member
The directions to modify the Cleveland heads are in the Motorsports catalog, have been for years. It's one thing to say something won't work, but to try and go about modifying something based on such a short amount of info would be truely idiotic. The pistons would likely be custom, although there are likely off the shelf parts available with the Nascar and Outlaw applications. Best thing to do if someone is wanting to go that route would be to contact Roush as they sell off all their used Nascar parts. But you're correct in that it isn't a simple bolt-on.
68stangman
New Member
The only heads I remember reading about that would give a benefit is a '69 or '70 351 head. The valves are somewhat larger. Intake is 1.84 versus 1.78, and exhaust is 1.54 over 1.46
They were great back then because they looked just like a 302 head, and your oponent could not tell your engine was better breathing. There were very limited aftermarket options back then. That head swap was about as good as you could get for the money.
Today, it would still be an upgrade, however, there is an aftermarket out there with better options. If I had the 351 heads already in hand, I would be inclined to use them. I would definately have them worked on. At least a three angle valve job and hardened seats (unleaded gas). I would also want bronze valve guides.
If I didn't already have them, I would not seek them out.
I'd just rather go aftermarket or rework E7's and have the 1.9/1.6 valves installed.
My .02
They were great back then because they looked just like a 302 head, and your oponent could not tell your engine was better breathing. There were very limited aftermarket options back then. That head swap was about as good as you could get for the money.
Today, it would still be an upgrade, however, there is an aftermarket out there with better options. If I had the 351 heads already in hand, I would be inclined to use them. I would definately have them worked on. At least a three angle valve job and hardened seats (unleaded gas). I would also want bronze valve guides.
If I didn't already have them, I would not seek them out.
I'd just rather go aftermarket or rework E7's and have the 1.9/1.6 valves installed.
My .02
1320stang said:
More horsepower, sure, but not necessarily more torque. Both of those racing series spend their time in an RPM band that isn't used on the street. That's why Boss 302s, for all their potential, were disappointing at the drag strip.
1320stang
Founding Member
68stangman said:
What are E7's and what aftermarket would ya'll recomend if i plan on having my cam have .533 Intake and Exhaust lift, a lobe seperation of 110 and 224 @ .50 (The Comp Cams 248HR)
65ShelbyClone
Founding Member
Max Power said:
That's right.....they also use titanium valves, 2.180" on the intake, a restrictor plate, and spin close to 11,000 rpm.
E7 is short for the E7TE heads, which all Stang 6.0's came with from 87-95. Also were used on the pickup & van 5.0 and 5.8 from 87-97. And ditto for the Lincoln Mark VII's from 87-91 (or whenever the VII was replaced by the VIII). Aftermarket heads is personal choice, but for the street on 289's 302's and 331's, those having no larger than 1.94 valved intakes will work fine. 2.02's are really overkill and you also run the risk of valve relief interference wit many pistons, due to the reliefs being too small. There are so many choices out there now it's up to you. I went with Canfield's due to the deal I got on them ($1100 shipped, bought em on ebay) and I couldn't have made a better choice. Mine are the 1.95 valved heads that are the equivalent of AFR165's.bad68coupe said:
68stangman said:
How large are the e7 valves?
and what about GT40 heads?
i was also interested in the GT40P heads but i heard they require some sort of special header is that correct?
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