ok first of all.. ive been told that the 351m is a 400 block with a smaller bore.. can you bore it out to 400?
next q is what is the diff between 351m and 351 windsor? is it just a few diff parts like heads and shit? will windsor heads fit the 351 modified block? any other diffs in the engines?

351m is part of the big block family 351m 400 460 429. 351w is small block family 289 302 351w NO 351m to 351w parts will not inner change. 351m to a 400 is stroke not bore.:evil:

351M is part of the 335 engine family along with the 351C and 400. Some parts interchange with the 351C but not many. The main differences between the 351C and 351M-400 are the block heigth, crank diameter, distributor, intake manifold width and bell housing bolt pattern.

The 351M and 400 share the same bell housing bolt pattern and distributor as the 385 series 429/460.

The differences between the 351M and 400 are the crank, 3.5" stoke vs. 4" stroke, and piston compression heigth. They both have 4" bores. Everything else is pretty much the same.

Virtually nothing is interchangeable with the 351W without modifications.

The 335 series heads can be fitted to Windsors, ie: Boss 302 or 'Clevor', and intake adaptors are available,the bore spacing is the same, so it may be possible to fit 351W heads to a 351M with some weird intake adaptor , but probably not worth the effort.

so to make my 351 a 400, i get diff crank and pistons? correct?
and i may have rust in my cylinders.. and if this is possible what is the best way to repair this?
do nothing?
take to machine shop?
if i take it to a machine shop and they bore it, how much bigger can i safely go w/o making the walls too thin?

Take it to the scrap yard!

so to make my 351 a 400, i get diff crank and pistons? correct?

Yes

and i may have rust in my cylinders.. and if this is possible what is the best way to repair this? do nothing? take to machine shop?

Uhhh......how bad? Most rust is just 'seasoning' but JY blocks are CHEAP.


if i take it to a machine shop and they bore it, how much bigger can i safely go w/o making the walls too thin?

Most agree 30 over is max.

so to make my 351 a 400, i get diff crank and pistons? correct?
and i may have rust in my cylinders.. and if this is possible what is the best way to repair this?
do nothing?
take to machine shop?
if i take it to a machine shop and they bore it, how much bigger can i safely go w/o making the walls too thin?
Hey I see your located in Kansas I live about 45 mins south of Kansas City In MO. I just pulled a running 400M that is still virgin bore out of my 77 F-250 with 80,000 original miles if your interested I ll sell it cheap I did have to pull the oil pan and Im sure it could use a freshning up but it would get you all the parts ya need for a 400 send me an e-mail at robertsslomaro377@yahoo.com

351c, 351m 400's and the 385series engines share the same distributor.

You can swap heads from the windsor family to the cleveland family and vice versa, intakes spacers can be purchased to do this (price motorsports is where i got mine), 400's did come factory with a small block bellhousing pattern, rare to find but they are out there (iirc, they came with a fmx tranny). there is also more in common between the 400's and 351c's, ie all the valve train less the push rods will swap, and with the use of intake spacers, all heads and intakes will swap between the two as well (even the high port nascar heads). You can use any 351c piston in a 400 if you bush the con rod to the cleveland pin diameter.

BTW 400's are NOT big blocks, even though ford doesn't technically classify their engines as big block/small block, they are classified in engine series, however if you must classify the engine it is way closer to a small block then a big block.

351M is part of the 335 engine family along with the 351C and 400. Some parts interchange with the 351C but not many. The main differences between the 351C and 351M-400 are the block heigth, crank diameter, distributor, intake manifold width and bell housing bolt pattern.

The 351M and 400 share the same bell housing bolt pattern and distributor as the 385 series 429/460.

The differences between the 351M and 400 are the crank, 3.5" stoke vs. 4" stroke, and piston compression heigth. They both have 4" bores. Everything else is pretty much the same.

Virtually nothing is interchangeable with the 351W without modifications.

The 335 series heads can be fitted to Windsors, ie: Boss 302 or 'Clevor', and intake adaptors are available,the bore spacing is the same, so it may be possible to fit 351W heads to a 351M with some weird intake adaptor , but probably not worth the effort.

Yes



Uhhh......how bad? Most rust is just 'seasoning' but JY blocks are CHEAP.




Most agree 30 over is max.

4x is correct on all counts!

351c, 351m 400's and the 385series engines share the same distributor.

You can swap heads from the windsor family to the cleveland family and vice versa, intakes spacers can be purchased to do this (price motorsports is where i got mine), 400's did come factory with a small block bellhousing pattern, rare to find but they are out there (iirc, they came with a fmx tranny). there is also more in common between the 400's and 351c's, ie all the valve train less the push rods will swap, and with the use of intake spacers, all heads and intakes will swap between the two as well (even the high port nascar heads). You can use any 351c piston in a 400 if you bush the con rod to the cleveland pin diameter.

BTW 400's are NOT big blocks, even though ford doesn't technically classify their engines as big block/small block, they are classified in engine series, however if you must classify the engine it is way closer to a small block then a big block.

I agree with everything except ....


351c, 351m 400's and the 385series engines share the same distributor.

I thought the 351C dizzy wouldn't swap because of the same reason the push rods don't.....different block height. Is that so? I've never had a 351C so I don't know for sure.