I bought a 400 at a farm auction today, came with 4 wheels a cab and an 8' box.

 

It did include pre-installation prep, however it's more than I want to spend. I'd rather go .030 over on a new block than pay that much to go back to stock.

 

Yea yea rub it in.

 

Sorry, I couldn't resist

 

Well if there ever was a 351M/400 made up of about 5 different engines, it has to be this one.

I checked a few of the date codes, and I highly doubt half of the parts I picked up are original to this block.

Original Engine Assembly Date: 78C21 = March 21, 1978
Engine Block Cast Date: 8B28 = February 28, 1978
RH Exhaust Manifold: 9F4 = June 4, 1979
LH Exhaust Manifold: 9B14 = February 14, 1979
RH Cylinder Head: 8G5 = July 5, 1978
LH Cylinder Head: 7L28 = October 28, 1977

I'm guessing that when Ford stamped the engines with the assembly date, the engines were near complete, and not just a long block. Maybe I'm wrong, but if not, this truly is the 400 of many different 351M's and 400's.

To add to that. somebody had written "400" in white paint pen on the underside of the block. When I was cleaning some of the grease off, I realized that under the 400 was "351". So, either somebody made a mistake when they were documenting which engine this was, or this block used to be a 351M, and had a 400 crankshaft installed.

 

Didn't the 351M block have a different code than the 400's?

 

Only if it was in a car. Any truck 351M/400 should be D7TE, while the cars could be D5AE or D8AE.

 

Ok, good to know. And, where is that shown? Can I find it w/o pulling things off? If so I could check both Rusty and Dad's.

 

You'll have to put your truck on the lift, but you should be able to see it then. It's on the passenger side of the block, right above the starter motor. It's pretty close to the head mounting surface.

You can also check the cast date of your block as well. That is located on the back of the block, right under the oil pressure sending unit. I'd be really interested in what both of your blocks have for that.

 

M-Block 351M/400 Parts Reference