I just recently picked up a 1976 Ford LTD with the 351m400 in it. I want to take the motor out of it and put it in my 1968 Ford F250. In the truck I have a 360 with a 4spd tranny and I was wondering if the tranny will mount to the 351m400. If so, is there any modifications I would have to do???




Thanks FORD_MANIAC-68

 

I have not done this specific swap but I can tell you with certainty that you will need a bell housing and flywheel for the 351M/400. The 360 is an internally balanced engine and the 351M/400 is externally balanced, meaning that there is a counter weight cast into the 351M/400 flywheel.

Engine mounts may be required as well. I will leave that for someone who knows for sure.

 

Given the age of these trucks and the possible number of owners, what four-speed is installed behind the 360?

 

The 351m and 400 were two different engines. The 351M was a short stroke modified 400 and only put in trucks from 78-82. The 400 was in cars in the early 70s, and in trucks from 78-82.
The 400 could have a small block or big block bell, I do not know of any pattern to what cars got what pattern, but the trucks all had the big block pattern.
Since it was a standard bolt pattern you can fit up any of the truck four speeds with the correct bellhousing. You can use the perches and mounts for a 78/79 F100 to mount it, but the bell is different than the FE.

 

The 351M and 400 shared the same block except for the 1973 400 installed in full sized Ford cars with FMX automatic transmissions (Quoted from Tom Monroe's book on how to rebuild 351C-351M-400-429-460). Basically, all 351M & 400 engines built after 1973 had the same bell housing bolt pattern. Also, the 351M & 400 were first installed in the trucks in 1977.

 

By '76 the 400 is the 385 series big block pattern.

Back to the OP. What is wrong with your 360? There is no gain from a stock '76 400 and a loss from any year stock 351M.

IMO rebuild your 360 if it's worn out, and even if you keep it stock you'll be miles ahead of trying to do this swap.

 

The 360 that is in the 68 only has 44xxx original miles but either the timing gear broke or the camshaft gear did. I have yet to pull it apart to see. I'm wanting to put the 351m400 in the truck so I can pull the 360 out and completely clean and rebuild it....... as for the 351m400 the sticker that is on the valve cover says its a 351 modified 400. Kinda all I know about it at this point.



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After a short lil research I found out the motor in the ltd is just a 400. Still researching why the sticker says 351m400.

 

You do know that 67-72's odometers reset to zero at 99,999 so your 360 might have 100,000+44K on it unless you have had it for the last 40 years. I believe that the sticker you are referencing is the emissions sticker which references all pertinent info about the 351m/400 engine family. The two use the same block so are essentially the same motor except for stroke which is kind of like the FE family which uses the same block.

 

Yes I do know the odometer resets at 99999. An I do know that there is only 44xxx orginal miles on it as its only been owned by two other ppl an was used as a farm truck and parked for 15 years before the guy I got it from owned it and he only had for 6 months.........

 

The sticker should read something like :
351/400 modified engine family________400. If it's a 400.
351/400 modified engine family________351. If it's a 351.
It would be ok if you found a 77/79 Dent to get all the parts around the 351/400 to stab it. But outside of that seems like too much to be too temporary to me. Those 351/400 smog motors were dogs compared to a FE. Sure you can build 'em, but you are talking about this 351/400 being a "tweener".
My .02.

 

It's not a bad engine, I have a 400 in my box van with an Edelbrock intake and carb, and and it has a fair bit of power.

 

Again, jmo, but to make this swap as a temporary motor is too much work and changes.

 

Hot Rod Magazine affectionately called he 351M/400 "The Mutt" due to the off-brand parts they used to make over 500 HP.

Here is a snippet from the article linked below:

"Engine designs can be a lot like politics: Sometimes the results are inspired-like Chevy's small-block or the classic Chrysler Hemi-but quite often the finished product is a big, fat compromise that nobody particularly loves. That second scenario was the case when Ford debuted the 400 in 1971.

The 400 was intended as a replacement for Ford's aging big-block designs. The block's architecture borrowed heavily from the Cleveland, including the bore spacing, but 1.09 inches of additional deck height were added to allow a 4.00-inch stroke and the potential for plenty of torque. Unfortunately, this engine's debut was also horrifically timed. The confluence of increasingly harsh government pollution standards and the disappearance of high-octane leaded fuels left the 400 castrated in terms of its performance potential. A retarded camshaft, low compression, open combustion chambers, and other smog-control measures conspired to drop the rated output for this 400ci engine to a pathetic 158 hp between 1975 and 1978."

Read more: How We Got Over 500hp from Ford's 400M Engine - Hot Rod Magazine