carb and heads
Junior User
Joined: Sep 2002
Posts: 67
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From: Charleston USA
carb and heads
i was told that to put a 4bbl carb and a matching intak that i have to change my heads on my 351m? i was wondering if this is true. i know very little about these engines, it is my first one. and since it is almost the same as a 400, is the 351m concidered a big block? and also 351c heads will fit right???
Senior User
Joined: Dec 2001
Posts: 356
Likes: 0
From: space city
carb and heads
from what i hear, you'd have as much luck finding a 351m/400 factory 4v intake as you would finding an aluminum block & heads boss 429 for $100, so you'd be using an aftermarket intake.
you don't have to change heads - all 351m/400 intakes have the "small" ports, so any one of them will go right on. 351C 2v heads will also go right on, but the only difference is in the exhaust ports, and i think the early 351m/400 heads may not have the "pot-belly" restriction anyway.
if you're doing a complete rebuild and can get the 2v heads pretty cheap, then do it - but if you just want to spice up a motor that's running good, then just swap the intake & carb - and maybe throw on some headers & a hotter cam for good luck!
you don't have to change heads - all 351m/400 intakes have the "small" ports, so any one of them will go right on. 351C 2v heads will also go right on, but the only difference is in the exhaust ports, and i think the early 351m/400 heads may not have the "pot-belly" restriction anyway.
if you're doing a complete rebuild and can get the 2v heads pretty cheap, then do it - but if you just want to spice up a motor that's running good, then just swap the intake & carb - and maybe throw on some headers & a hotter cam for good luck!
Posting Legend
Joined: Sep 2001
Posts: 30,255
Likes: 37
carb and heads
>i was told that to put a 4bbl carb and a matching intak that i have to change my heads on my 351m?
>
No -You use an Edelbrock or Weiand 4bbl manifold with your 351m heads which are basicly the same as 400 or 351c 2V heads. There are minor differences over the years.
>i know very little about these engines, it is my first one.
Read the posts here, follow the links, check the technical papers here also. You can learn a lot just by reading, then when you get to a point you just can't figure out ask :-)
>and since it is almost the same as a 400, is the 351m concidered a big block?
>
The engine has parts in common with the 351c smallblock and also with the 429/460 big block. So it is referenced both ways. The 351m and 400 block is exactly the same.
>and also 351c heads will fit right???
Right
