so bill, im gonna take pics of my block and post them if i can. so you can see it really does say DIF on it.

 

any difference between the blocks from the dearborn foundry and the ones from cleveland?

 

near as i can tell, no. what i do know is my block comes out of a 1972 ltd and is the orig engine. the dif casting info is on top the block. i have no cf in the right side at all.

 

GT40man,

Hey, I just found a 1971 400 from a '71 Galaxie that has the DIF casting mark on the back. Block casting number is D1AE. I hope to pick it up for analysis by this weekend.

All the M-blocks I've seen have the casting plant (foundry) mark on the top rear, next to the oil pressure sending unit hole. Cleveland blocks (CF foundry mark) have the casting date codes on the side, down by the block part casting codes. Michigan blocks (MCC foundry mark) have the casting date codes up on top, right next to the MCC mark.

The DIF block I found doesn't have casting date codes on top either.

As for differences in the blocks, the only significant differences I've found are in the later D7TE and D8AE blocks, which have revised main bearing support webs. That's the reason that there are two different main bearing sets for the M-block, pre-'77 and '77-later. I haven't found any significant differences between blocks within the same generation (i.e., pre- or post-'77), but from different foundries.

 

woo hoo another dif block. so what does dif mean? when i broke it open, i had flat tops in it, the car was junked cause the owner didnt want to rebuild an engine. so i got an orig 9:1 400 i think.

 

ok here we go, i fond this on the DIF.

Additional cast codes on the block: DIF means Dearborn Industrial Foundry. All 352 blocks have the number 5750603 cast on the right side of the area of #1 cylinder: Dearborn cast this number upside down, Cleveland right side up.

this is an edit from the 58-60 tbird page.

 

If the engine did come out of one of those old 70s land yacht cars then most definatly its not a 351M and its a 400. The 351M was never used in the cars I should know I have stripped a few of them as my dad used to like these cars. He took 400 Ford engine out of the one of the cars and repowered his 82 GMC 3500 dually flatdeck. He hates Chevy engines but likes the way the truck rides as the Fords ride like a tank so he made a Chev/Ford out of her.

Anyhow good luck
KW

 

the 400 was made from 1971-1982

the 351m was made from 1975-1982

 

Sorry to reopen this old thread. Maybe bubba f250 can look as well. My engine is a 400 out of a 1972 ltd, with a dif for casting information. I was looking at my heads and I have the same DIF casting with a D1AE-A1 for a part num as well on the heads.

I tried to measure the port size and they appear to be @ the same as the 351c diae heads. the head volume according to the ford parts interchange book is 74-77cc.

ports are 2.02 x 1.65 intake 1.84 x 1.38 exhaust
valves are 2.04 I and 1.67 E

bubba you can add this to your head compilation

 

 

What is the best way to I.D a 71 400?

 

By looking at the casting codes.

Looks like you're hijacking a 15 yo thread to ask questions that have already been asked and answered....

 

O wow, I had no idea?
What casting specifically calls out 71?

 

Yes...I know this is an old thread, but I have to correct this idiotic info.

351M: 1975/79 Ford/Merc Passenger Cars; 1977/79 F100/350; 1978/82 Bronco; 1980/82 F150/350.

 

I think the 351M was an option in the 77/78 LTD II & Thunderbird, my mom's LTD II had the 302.

The iron castings will show the foundry they were made in, the casting date (mo/yr) and a few other details cast into the iron.

Someplace stamped into the block - behind the timing case? - the block gets stamped with something of an Assembly Date.

Bubba's site (in the Sticky) shows all sorts of neato information on these things.