Im building a new 351M for my truck its nothing special YET im startin from motor and tranny (4 speed) im just usin it for play mud, rock or what ever me and the friends wanna do with it can anyone gimme some advice on how to build the motor other than 4 bbl and a mild cam? I would appriciate any advice that you could give me  

If you are intent on building an M at least put a 400 crank in, with a 4" stroke it helps with torque output, If you can't find 1 easily I have several in stock, whatever you do use good quality bearings throughout, preferably clevite, and a hv oil pump is MANDATORY to keep the bottom end alive, you can bolt on a set of closed chamber australian cleveland heads to really liven the slug up,have those as well, check out my website at www.jandmdrivetrain.biz, let me know if you have any other questions or are looking for parts, I'm a FORD guy myself and have done lots of buildups  

I agree on the 4" stroke 100%. Also buy a good timing chain, OEM is retarded about 8 degree's if I remember correctly. Another good guy to talk to is www.mpgheads.com ford man. Cuts his own cams and just about anything else. I use this guy myself for some of my odd projects. Working on a 400 ford with d3ze 4barrel cleveland heads. Never built a engine like this so been wanting to for a long time. It'll be interesting. Going in a 4wd truck. On the btm end living with the 351m/400, restrictors up to the camshaft helps a lot. keeping oil on the crankshaft. Also if your running high rpm drop me a note on more info. make sure our ford guys run well.  

You didn't mention a year model or size on that truck, but just a couple of things come to mind: I'm a Windsor fan myself so I don't know how relevant this is to 351M's, but when you change strokes and heads and possibly bore oversize- you should be mindful of what compression ratio you will wind up with. Keep in mind that the cam you use will act smaller with these mods compared to the specs for the 351M. It goes without saying that a good dual plane manifold and full length headers will help those heads breathe better. One other point-rock crawlers need low end torque while mudders need high rev screamers, so one engine cannot do both well.  

i'm not sure but it seems that somewhere i heard of using the 400M's head aswell, not sure though.  

The only real difference between the 400 and the 351M is in the stroke. I'm 98% sure all the parts interchange. I just figured out the best upgrade for that 351M:turn the M upside down!  

doug351:
The only real difference between the 400 and the 351M is in the stroke. I'm 98% sure all the parts interchange. I just figured out the best upgrade for that 351M:turn the M upside down!

i agree with you, but just trying to help this guy out  

well I wouldn't stress much on helping em out he's a one post wonder 4 months ago!  

whoops didn't even look at the date.  

One advantage of the 400 is you can stroke it to about 4.230 on crank. thats awesome but cylinder side load is another issue with pistons. Need a longer skirt on piston to help keep straight. I like the larger mains on a 400. Currently doing a 400 ford with cleveland 4v heads and some other cool stuff for a 4wd. The best way to upgrade a windsor is add cleveland parts on it and make it a clevor. The canted valve design is a better design over windsor head design.  

This is true, but aftermarket heads negate the mods needed to adapt to a Clevor, and those heads are getting scarce.  

if you put a 400 crank in your 351 you will need to change to 400 pistons because the 351 has a much taller compression height and will hit the head if you use it with the 400 crank. or better than using the 400 pistons you can have your rod ends bushed down to accept 351c pins and then you have all kinds of aftermarket performance piston options  

One of the advantages over the windsor is the intake runner length is longer on a 400, that means torque. Deck height is the difference. The journals are bigger on the 400 than the windsor, less bearing speed in higher rpm's. Had several bottom end problems with windsor and expensive to upgrade. But windsor parts are available all over and now they have off the shelf parts to upgrade to canted valve heads with piston to fit. Cool stuff. Catch you later.