Off Roading Forums banner

How to tell if I received my original engine?

718 views 8 replies 4 participants last post by  **DONOTDELETE** 
G
#1 ·
I recently took my AMC 401 to a local machine shop. The engine is out of a 1978 Jeep 1/2 pickup and is going into my CJ.

I was wondering if there is any way to match the casting numbers to the vehicle? I ask because I'm wondering if I received my original block back from the shop. Here's the reason. When I received the block back, it is obvious that the engine I got back had a broken rod on the #2 cylinder because there is a lot dents and dings under the underside of the block. I don't recall seeing this damage when I tore the engine apart, but it could have been there and we never saw it. I also forgot to mark the block so I could easily identify it when I got it back.

So will the casting numbers match the VIN on the donor pickup in any manner? How about the casting numbers on the heads, will they correspond to the block in any manner? (These heads never went to the machine shop so they are the originals).

Thanks for the help,

Al
 
#3 ·
Hey Al,

as long is its for sure still a 401, and it isnt bored to the max, I woudnt be TOO worried, although a switheroo would sort of bite.

Hey Leve, that chart is GREAT!
 
#4 ·
that would be a little disconcerning, but the first thing I'd have to ask myself is, How many 401's does this guy have laying around? I'd guess NOT TOO MANY!
I'd just be glad I had one


brent
 
G
#5 ·
You guys are probably right. The engine is only bored .030 now, so maybe it won't matter. It would still suck to be taken advantage of like that. There would be nothing I could do anyway. However, it would either give me peace of mind if I knew it was my own block, or I would know to take my business else where next time if I found out he pulled a switch on me!
 
#6 ·
Don't all AMC V8's share the same block
? I was under the distinct impression that the only difference was that the heads for the 390 and 401 could not be used in the smaller displacements due to the valves physically hitting.. If that belief is true ........any old AMC block would look the same as another. I'm uncertain if there are internal differences (larger oil passages and such). If the guy screwed up the 401 block ..it would be a cheap correction to pick up a junk block and wipe his mess up with it.

Are the crank journals bigger on a 390/401? ....or is there any other distinctive difference between them and the rest of the AMC V8's? If so ...... I beg your pardon
..and please educate me
 
#8 ·
they are all visually the same, but you cant bore a 304 into a 401, or even bore a 360 into a 401. the cylinder walls arent thick enough

so really there are 304 blocks, 360 blocks, and 401 blocks, not counting the older 290,343,390 blocks


a virgin bore 401 is worth quite a bit!
 
G
#9 ·
I know this doesn't help now, but it might in the future. I usually punch a number or a "." on the block somewhere indescrete when I send a part to the shop. That way I know I recieved what I sent.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top