I am in the process of building up a monster offroader. I have a 351M from a 79 bronco with the 4speed tranny. I really like the transmissuion and the engine. However i have been told by some people that the 351M is not worth using on my project since it isnt a low rpm engine and a weak block aswell. I had plans of stroking it out and beefing it up. Should i stick with this plan and will it be worth it cause i am looking to get torque numbers in the upper 400s if not more and horsepower in the upper 400s aswell. Is this realistic or should i swap for another engine. By the way a 460 will not work, unless it is fairly the same size as the 351. Also where can i get the stroker kit for it and what am i looking into price wise for this engine build up. thanks for you input.

 

First off, welcome aboard.

Secondly, I'll take a stab at this... The 351m shares the same block with the 400, all you need is a crank from the 400 and bammmm. There are not really any "stroker kits" for these, as far as I know. You can build the motor up to make the numbers you want, check out the gang on the "335 series" engine forum, they can help with more knowledge than I. Just a few thoughts on how much to beef, look at at least $1200 and then double it for safety.

--Mike

 

The 400 has the longest stroke of any V-8 pushrod engine made. It was made for torque. Unfortunately the engine was introduced at the verge of big emissions changes by the feds as well as mandated fuels changes. The 400 had difficulty coping with these changes. It was finally killed off by the electronic controls that later came along. It just wasn't compatible with the changes.

However, I have had 400's that have screamed, so----before you decide to do anything, read this: http://home.earthlink.net/~bubbaf250...history03.html

Many owners of Ford trucks that were originally equipped with M-block engines choose to upgrade their vehicles’ performance by replacing the M-block engine with a 385 series (429/460) big-block engine. In fact, this particular engine swap is so popular that an aftermarket industry has emerged to cater to it. (L&L Products, Inc. in Rowlett, Texas was originally founded specifically to manufacture and market components for Ford 385-series big-block engine swaps.)

On the other hand, an M-block engine in factory trim has vast, untapped power potential. It is smaller and lighter than a big block (which is why it was developed in the first place), and when properly built, the M-block 400’s power output is comparable to most big blocks.

Also, check this out: http://home.earthlink.net/~bubbaf250/index.html

 

Find a complete 400 and start fresh, blanace and blue print the block, flat top pistons no more than .030 over (351C pistons can be machined to work),, find a set of 351C 4V quench heads, or aussie heads (quench heads with 2V head valve size) find an intake of choice along with headers of choice, a holley 750 DP carb, then a cam to put power wherer you want it, the 335 series engines like compresion and cam.

There's a guy in the 335 engine forum that has a 800hp 400 (turned down crank and is now a 436 stroker) that he used to use in tractor pulling, but he wanted to move up a class so he built a 460 that could run nitrous.

 

There is a stroker kit for the 351m/400 motors. I think it turns it into 434 cubic inches if i remember correctly. I don't have any experience with the 434 but i do have a 400 that is bored out, 750 holley carb, edelbrock intake, comp cams 268 cam and it is a torque monster. It started off as a 351m but going to a 400 was a good investment. A built 400 is a good motor in my opinion.