whats kind of heads will interchange with my 351m

mustangrfast88

Founding Member
Sep 22, 2002
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middletown ohio
hi guys in need some help, it is not a mustang question but it is a engine question. i have a 351m in my truck and want to get alittle more power out of it and was woundering what kind of heads will interchange onto the 351m.
i have planned to do a cam heads and intake and full exhaust on it but i need to know what kind of heads will interchange.
i have found a set of i think 351 cleavland or windsor heads but dont know if they will work so if anybody has a answer for me i will be a happy camper or if you guys know of any other heads that will fit my 351m that will give it some more power thanks alot
matt
 
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-i'm not sure, but i think the cleveland heads should work? the 351 m was loosely based on the cleveland. if i recall correctly, though, the cleveland heads will create some space problems with the intake manifold. you might be better off porting the hell outa the m-heads. windsor heads will not work.
-there are many good cams out there for the m, so you're right on there
-same for the intakes, plenty of good ones out there
-not sure, but i assume there are some headers out there...
-if you're up to taking the engine apart, find a 400m crank and make a 400 outa that sucker
 
The c's have to be port matched and shimmed, the w's have to have major bolt hole mods. The 400m's might work, but I don't see much improvement over the 351's. I had a 400m with .050 shaved 351m heads for my dirt car, rv cam, had to run the 2bbl carb due to class. Scads of torque. (By the way, I believe edelbrock was the only aftermarket for 4bbl manifolds). If you can find a 400m block, it's an easy swap and you can use your 351m heads and most other parts. These blocks were produced during the oil crisis and CA emissions b.s., and although the "m" stands for modified, it in no way reflected the modifications toward performance. But they do produce monster torque. Hope that helps, and what more could one want in a truck?
 
i am not taking the engine out of the truck so a 400 crank is out of the question, but i think heads cam intake headers and new oil pump and it will run like a champ again

here is what i got planned
351c heads
edlebrock 4 barrel intake
rv cam
750 carb
headers
new oil pump
 
jcp, I believe they were identical, with the exception of the crank and rods, therefore (in my mind), why the 351m heads fit to a "t".

Fast88, I'm old and this was a while ago. I'm certain that major porting was necessary to align the heads and intake, as well as shims to make the intake fit on the heads. I just can't remember if it was the c manifold or the m. Sorry I can't help you more.
 
351Cleveland, 351Modified=400, have interchangeble heads, along with the 428 I believe. The 351 windsor, 302 windsor or any small block Ford, for that matter, heads would fit with mods, however, the best thing about the Cleveland was the heads, worst being the oiling system. The windsor had a great oiling system, crap heads in comparioson to the cleveland. Thus a smart man, made a CLEAVOR, a 351w with cleveland heads. The only problem was there was no manifold that had the correct intake ports. So, yes edelbrock makes one. Also some Aussie built Fords came this way.
At any rate, you need a set of Clevland heads.
(2v and 4v are differant) To make it worth your while, get the 4v and a 4v intake manifold. You'll be impressed how it wakes up that anchor you got now.
 
putting a 4bl head will be a pain in the ass. there is no intake for that. you would have to port the living crap out of one for it to fit. i built my brothers motor for his 81 f-150 4x4 and it beats or kepts up with mustangs.(no bs)
most likely close to stock ones

motor
400cid, 2bl heads just a quick clean up in the bowls, flat tops
elebrock performer,600 vac sec.
comp 268 hyd.cam,stock manifolds, duel exhaust
 
Well, my 2 cents...
Go with the 2bbl clevelands. I ran a 302 "street boss" or "clevor" engine for a while. The Valves and ports are huge even on the 2bbl heads. Unless you are planning huge RPM and Comp there is no need for any moptor to have valve sizes of the 4bbl 351C heads. I am not sure if any mods are necessary but there was not that much involved to put them on my 302 so it should not be to bad if you need to modify. I thought they just bolted up though? But then again, that thinking thing has got me into trouble before. :)
 
Get the 2bbl cleveland heads, they'll work a lot better than the 4bbl's, especially for a truck. You could also look at getting some aussie 2bbl heads, they have a closed chamber and would bump up the compression a little bit.
 
Yeah thats what I ran on mine ( the aussie heads), not so easy to find around here but I had a friend in Austrailia, he got me two sets, the second after I grenaded the motor. The power was amazing out of them above 3500rpm, but the stock 2bbl heads have 1.78 intake and 2.12" exhaust valve, thats way big, your cam choices will be very important. Make sure to research with several companies to get the one right for your combo. BTW my 302 was making about 350hp and was a very streetable daily driver. Got 18mpg in the city and 22 on the Highway. The torque was lacking though. Like I said the motor did not start pulling real hard till 3500rpm, and then it pulled hard to 6500
 
i agree, do NOT get the 4v heads for a tow vehicle - major PITA. my dad has those, he's got a '73 mach 1. it's the most cold-natured thing i've ever driven, and it hesitates like mad. they are just good for top-end (4000+) power (but lots of it). if you have to swap the C heads on there, make sure it's the 2v heads
 
so you guys are saying the 2v heads will work better on my truck then putting some 4v heads on it??? so if i put some 2 v heads on it i want the closed camber right, and if i use the 2v heads the edelbrock perfomer 400 intake will be a direct bolt on.
so does this sound like a better shopping list
351c 2v heads closed chamber
edelbrock pperfomer 400 intake
rv/ pulling cam
new exhaust system headers, and mac mufflers exit in front of rear wheel
new oil pump
new timing chain
anything eles you guys can think of
and any of thoise part any of you guy got laying around and want to sell for a good price pm me on them thanks matt
 
351c 2 bbl are almost identical to 351m-400 heads.The 351m-400 heads produced after 1975 with the D5 at the beginning of the casting number had a change in the exhaust port so it doesn't flow as well as the earlier ones.The Aussie 351c heads have a smaller combustion chamber for more compression but essentially the same ports as the early 351c 2 bbl heads.The Aussie heads can be found easily on eBay as well as different aftermarket 4 bbl manifolds.Most 351c,351m and 400 heads have a multiple groove system for the valve locks.The stock ford valves have a reputation for popping the end off when stressed so it is recommended you get some aftermarket ones.Starting around 1979 Ford Ford started using the single groove valve locks in 351m heads so these are better.A couple of real good sources of info on 351m motors are the forums at the Ford Truck enthusiast site http://www.ford-trucks.com/ and the cleveland forum on Network 54 http://www.network54.com/Hide/Forum/119419