I'm getting ready to rebuild the 351M in my '79 F150 4x4 and planned to increase it to 400 cubes. There have been many references to that article about 2 years ago where Hot Rod ( I believe it was them) built a 400M to approx. 468 ft lbs of torque using the Competition Cams extreme cam kit.

Has anyone followed this recipe and is the engine streetable? This truck is a weekend toy and does not go off-road except for during hunting season. Anyone build something similar? I don't need so many horses/ft lbs. I guess.

I have the info. in the tech articles on High Perf options in hand too.

 

I read the aricle you mentioned and one thing kinda scares me about it. They stated that this motor "should last 50,000 miles with no problems." To me, 50,000 miles is not much when you put $2000+ in a motor. My 351M now has 80,000+ miles on the rebuild with only one burnt valve which is common on these motors. If you dont want all of the power they are claiming, I would suggest more of an RV type cam and a little less compression to make it live longer. As for your other post, I have had good luck with Jasper motors and trannies. (The 351M mentioned was a home rebuild, though.)

Nathan

 

Nathan,
I agree about the 50K miles. I'd rather have an engine which longer lived. We just moved from Seattle to Philly and I haven't located my copy of that article yet but did search it out and made a copy at my local library (Sept. '98).

Thanks for the input on Jasper Engines too.

 

I agree with the 50k. They built this engine for HARD running purposes where it WILL get the crap beat out of it, probably day in and day out. You can't expect to get 100,000 out of any engine like that.


I'm building mine almost identicle, cept for cam. I just ordered a Crane 278°, specs out to 222° at .050".
I rebuilt the heads myself at a tech school engine course, and shaved them .025". The block will probably stay put untouched. I'm not doing the porting/polishing or port matching although, and am gunna run fenderwell exit hedman headers on my 78F150. I'm also gunna run a 2,000rpm stall converter, have 3.50 gears and 31" tires. It should pull like a freight train!

 

this is just a old thread I dug up, but you guys have to remember that the engine that is supposed to never need touched for 50,000 miles was also built as cheaply as possible, for pete's sake they didn't even have it balanced...

 

I didnt have my 80,000 mi motor balanced, either. Other than stock parts and careful assy., I used an Edelbrock Performer intake, cam, and carb, and had around $2000 in it. My only regret is not making a 400 while I was doing it. 80,000+ and still gruntin', no smoken, leakin, starts right up, even on the coldest mornins.

Nathan

 

Well, my opinion goes against the grain of everyone else's quite a bit. Mine is simple, if you don't want that much torque and are worried about longevity, scrap the M-block and go with a 302 or a 351-W. I like them MUCH better anyway. Further more, from what I have been told, you take a crank DIRECTLY from a 400-M and put it into a Windsor and you'll have a 400 cube Windsor. I'm not sure on that, but I will check. Other half of my opinion is this, if you DO want power and torque.....AGAIN scrap the M-block and go with a 429/460. I'm strongly dislike the M-block from personal expierence's and from first hand seeing other's problems with them. Good luck on whatever route you take.

Rob
"Stuck with a m*par, Settle for a ch*vy, Happy with a Ford!!!!"

 

The problem with putting a M crank in a 351 block is you'd have to use the shorter Windsor rods because the M deck is 3/4" taller and you'd still end up about .16 in the hole so you'd need custom pistons or a hair longer rod. Either way you'd end up with a very poor 1.4 and change rod ratio. It would'nt be a good engine.

Since the 385 series and the M share bolt patterns and such I think the cubes are the way to go.

 

Here is something else to think about. If you are replacing the engine then go with a 351W. Parts are readily available anywhere and you get get gobs or power if that is what you want. I was getting ready to do the same swap last year. After doing lots of research, lots of reading etc finaly I was talking to the guys at the Ford Technical Hotline and they convinced me very quickly to forget the older technology. There is no reason to build a 351M engine when the newer 351W engines run so strong. You will save lots of headaches by going with a newer, readily available engine. Cost will be the same and when you get done you will have a modern upto date engine. The Ford hotline number is 810-468-1356. I would call these guys and talk to them they are very knowledgable and can help you make the right choice.

 

How did they suggest adapting the small block to a big block trans. Id jump at the chance, but I have a rebuilt c6 and dont want to loose it to get a small bolt pattern. Ive been looking for an adapter for this combo, but havent found one. Funny because I did find one to put a TH400 behind a small Ford. What good is that!?

Nathan

 

Nathan, there are plenty of C6 trans with a small block bell housing. I've seen several for sale on the web and my local junk yards have them as well. Just call around and you should be able to find one. There are some excellent used parts dealers on the net. The C6 was used in heavy duty applications by ford in trucks and vans with a 351w. Hope this helps.

 

I don't know guys. Not only are we talking about finding a "baby" C6 but you're looking for a 4x4 set up. The junk yards here won't separate them and the cost of converting the 2 WD C6 to mate with the T case is also an extra cost.

Go with a 429/460. They're like $165 from pick your part out of '69 Lincolns.

Good luck

 

I know their available, I even have one just sittin around. My big block tranny just got a $800 rebuild not long ago and it works great! Id like to get my moneys worth out of it. Im either going to build a 400, or bite the bullet and build a 429/460 and just pay for the fuel to run them$$ Hey, if you want to play big, you gotta pay big!!

Nathan

 

let me tell ya friend,i wouldn't waste a dime on the 351/400M. engine . you need to go with a 1968-thru 1971 429/460 engine. the engines itself without doing a thing is already 360hp. and 500 lb. ft. of torque with 429or 460 cubic inches. with out spending a dime. these are far superior to any 351/400 engine. i have one in my 77 f-150 with open chamber '72 heads with a little exhaust port done myself bored .060 over on the block, if i remember right 19 or 22 cc. dished pistons. Stock bottom end everything is factory right down to the bolts.stock rocker arms,a crane part no. 353942. l&l heaarders, a dual plane intake, and a holley 750 double pumper carb, and a true roller timing chaain. that's about it and i can say it will tear up the tires till i let off the gas. i was talking to the l&l rep that sold me the headers and he has a similar setup. 40hp. by just bolting on the headers i could really feel the difference by putting them on, and horse power a very conservative 425 hp. and i'll tell you this motor has all the stump pulling power you will ever need it currently has over 100,000 miles on it on still going strong i beat the ##### out of it all the time and it keeps trucking along. if you want to a conversion foor your truck a 429/460 will blt in with minimal problems, it will bolt to your trans. call L&L products 1-800-526-0064 that's the number out of four wheeler mag. for a quote on a conversion kit for your truck. trust me you will glad you went with a 429/460 money well spent. take it easy Ray .

 

No offense, but this is about the 400 engine. If we wanted to be told how 'superior' the 429/460 is, we would've asked. Whats next, the Chevy guys gunna come in and shove their 350/454 bull down our throats too?