351 to 400

[79-4x4]

what does it take to make a 351m a 400?
and how much better/worse is it?
thenka for any help.

 

[Billz4x4z]

what does it take to make a 351m a 400?
and how much better/worse is it?
thenka for any help.

[snapback]16930[/snapback]​

Just a matter of changing the crank and pistons is all.
You'll gain some extra power.

 

[dezracer]

what does it take to make a 351m a 400?
and how much better/worse is it?
thenka for any help.

[snapback]16930[/snapback]​

Put a 460 in instead, it will bolt up to your trans and then u could put in some 3.50 gears and have a sleeper

 

[79-4x4]

what is a sleeper???????????
i do not thinh i want to put asmush gas in it that a 460 would use

 

[12oz_racer]

you have to change the crank and rods, but really isn't worth it for the trouble. and a 460 really doesn't eat much more fuel and you have the power.

 

[a1bummer]

It's a bit more than just changing the crank, rods, and pistons. If I remember right the 351m and 400 both have the same bore which would make the pistons the same. The 400 has a longer stroke and deck height to come up with the added displacement. What your asking for is what's called "stroking" and engine. The crank from a 400 may fit into the 351m without modification. Then you would have to find the right connecting rod and piston configuration to fit you application. One or the other if not both would have to be aftermarket or modified to fit. If you simply changed the crank and rods the pistons would extend past the top of the deck. And a "Sleeper" is a vehicle that looks mild or slow but really blows the doors off the competition.

 

[badass79f150]

It's a bit more than just changing the crank, rods, and pistons. If I remember right the 351m and 400 both have the same bore which would make the pistons the same. The 400 has a longer stroke and deck height to come up with the added displacement. What your asking for is what's called "stroking" and engine. The crank from a 400 may fit into the 351m without modification. Then you would have to find the right connecting rod and piston configuration to fit you application. One or the other if not both would have to be aftermarket or modified to fit. If you simply changed the crank and rods the pistons would extend past the top of the deck. And a "Sleeper" is a vehicle that looks mild or slow but really blows the doors off the competition.

[snapback]17139[/snapback]​

you are right about 400 having a longer stroke than the351m but it does also have a bigger bore. the bore on a 400 is 0.40 over what the bore on a 351m is. you might also have to swap the heads because the 400 has bigger intake and exhaust valves than the 351m has. it will be some work i suggest that you do what i did. find a old 400 motor that is complete and has low miles and just buy a rebuild it for about $200.00 and gasket kit.