I'm trying to figure out which motor is in my buddy's 1970 Pontiac Trans Am Clone. Without pulling the motor or the heads the only numbers that I can find on the block is up near the water pump ZJ 0453448 and then in the back near the distributor is A148 75.

 

1973 Super Duty 455 is a ZJ code, with manual transmission.

If yer gonna pick one, that'd be a top 5 choice I believe, ...



(Google is your friend, ...)

 

I've used google and I found a '73 455 and '76 400 and '79 400 that are ZJ block ID numbers too.
http://www.transamworld.com/fbird-history-php2.php
http://www.spottsperformance.com/engineid.htm

http://www.yearone.com/updatedsingle...ontengid4.html

 

Can any one else help?

 

If the block is a true pontiac block and the number you got off the dist pad is 75, all I can tell you is that its a 1975 block.
Pontiac stamps the block its displacement on the side of the block towards the front freeze plug. You have to look at it frommthe bottom.

 

From my sources I'd say its a late 1974 400cid engine. It should have came stock with
4c Heads on it.

 

Thanks guys I will take a look at it tomorrow and let you know what I find.

 

Question....I'm not to versed when it comes to Pontiac's but is the 400 a big block?

 

From a distance you can't tell one Pontiac block from another, 350-400-428-455, they're all the same. There is no 'small-block', 'big-block' like Chevrolet blocks.

There's also the earlier 326-389 added to the list, ...

Sounds like no one can give you a definite answer yet, ...

 

Thanks PontiacFan......you Da MAN!

 

Looking at the passenger side all I can see is two freeze plugs....I can't seem to find any numbers but that thing is dirty as hell.