ok so i have a 1978 F150 which i was TOLD had a 351m in it.. but further research of the block code located above the starter is saying i have a 400. so. i dont know what to buy parts for.. the code is D1AE 6015 AO. help?????? anyone please.

 

Block for the 351M is the same as for a 400. The only difference between the two is the stroke. That's also the only way to tell the difference between them, measure the stroke.

 

Correction. AC as last two letters of the block code. and i read the casting numbers for the m blocks started with D7TE not sure if thats true or not. so how would i measure the stroke??? what would the difference in the two be? thanks for all advice. it is GREATLY needed

 

also. found out that my particular truck came off the factory line with a 400 c.i 6.6 liter engine. but im still not sure if thats the original engine.

 

Bring engine to TDC #1 and pull the spark plug. Stick a long dowel or rod through the spark plug hole untill it bottoms against the piston and mark the rod. Rotate the engine on half turn and insert the rod again and mark it. Measure the difference between the marks, that's your stroke.
3.50"=351, 3.98"=400.

 

Engine's been swapped, not an uncommon occurrence on a vehicle this old.

D7TE-6015-AB, -A1B, -A2B = Block casting numbers for 1977/79 F100/350 & 1978/79 Bronco with 351M/400 engines.

D1AE-6015-AC = Block casting number for 1971/74 Passenger Cars with 400 engines.

The engine code is the 4th digit of the VIN

1977/79 F100/350: B = 300 I-6 / G = 302 (F100/150 only) / H = 351M / J = 460 / S = 400.

351M/400 not offered for F100/350's prior to 1977, nor for Bronco's prior to 1978 / 400 introduced in 1971 Passenger Cars / 351M in 1975 Passenger Cars.

 

Ok so now that I know what I have I am in need of a plate that goes between the engine and bellhousing . I am eating up my starter and flywheel when I try to crank it. Has 180 tooth flywheel. Got a plate on it but its for a automatic tranny. Mine is a four speed had to cut where the starter goes to make it work. So I'm not exactly sure what the problem is. Could you guys help with this? Suggestions???

 

I have searched all over the internet for a motor plate and cant seem to find one

 

If the flywheel has been worn down even a little bit, it may cause even a new starter or drive gear to shear as well. I ran into this problem myself and had to change the flywheel. After changing the flywheel and adding a new starter gear everything works fine. As for any difference between the plate between the trans and motor, I'm not sure. But I would inspect the flywheel all the way around (if you haven't already) before buying anymore parts. Just a thought, good luck.

 

Well i bought a new ring gear for the flywheel and drive gear for the starter about a month ago and had the ring gear pressed on and the drive gear put in my starter and it still grinds.also this is not the original starter. Before I got the truck it had a auto zone remanufactured one on it. Could this be part of the problem?

 

I have started a new thread on the starter topic. Its under starter and flywheel problem, if anyone could help

 

You will need the manual flywheel and starter. I don't know a lot about it but this will bump this thread s others will see it.

 

Didn't see your other thread glad you got it figured out.