Is the block from a 1963 15H 389 (out of a Catalina) and the block from 1 1976 400 the same?? Will i have any problems putting the 389 in my 81 TA ?? Any help is greatly appreciated.
C  

Short answer is NO.  

I have both a 1963 Tempest LeMans 326HO with a 1963 389 block and I have six Gen-2 Firebirds of various flavors including a 1981 with 1967 400 in it.

The bolt pattern on the side of the block is different, but there are adapters to solve that.  

The big problem is that the 1963 mounts the starter in the bell housing whereas 1965+ (including 1981) mount the starter on the block.  It is possible to machine the block to mount a starter, but that's not easy or cheap.  

The 1963 block uses 7/16 NC bolts for the bellhousing to block whereas 1965+ uses 3/8 NC bolts.  

The 1963 block has provision for thru-stud oiling and 1965+ heads use thru-pushrod oiliing, but the former can be tapped and blocked.  

There are also some other differences that are minor.

IMO, you are better off finding a 1965+ 389 or whatever CID block.

Craig  

Thank you for the reply. I guess i have an engine for sale or maybe trade. :-(
C  

Don't take this the wrong way -- like I posted a response to sell something -- I did not.  But, I do have a few extra blocks/cranks that I have no plans for at the moment that would work for you, but you'd probably need to be within range of Las Vegas because I don't think you'd want to pay shipping on something that heavy.  Local pickup might be worth it to you.

PM or email me if interested.  Otherwise -- good luck!

See this website for some of my other projects:

http://www.originalho.com

Craig  

I am in no way offended. I was hoping this engine i bought would fit, so i didnt have to rebuilt an engine from bottom. I dont know enough about that stuff to do that. I was hoping to find a ok running engine to drop in with 250-300 hp. Would you have an complete engine like that for sale??  

Yeah maybe.  PM me so we can take this offline.