If your engine block is a 1964 block,the 25K coded engine came from the factory in the big cars like a catalina,bonneville,star chief,or grand prix.The heads you have are probably the correct heads for your 25K block,if you scrape some more gunk,they are probably a 9773345.That 25K block is a 303 horespower rated 389 from the factory with a 10.5 copression ratio.The 4 different engine codes you sby 1965gtoragtop - Pontiac GTO Forum
Anyone have a 64-65 gto engine/block? Anyone have any 65 gto "77" heads? Thanks,Kevinby 1965gtoragtop - Pontiac GTO Forum
Thanks for the heads up on the YZ block advertised on the web site.I contacted the guy and it was sold.So,i'm still looking for a 1969-70 YZ and WS block and a 1965 WS GTO block.Thanks,Kevinby Kevin Black - Pontiac GTO Forum
Howdy ,I'm looking for a 400 YZ coded block .Thanks,Kevinby Kevin Black - Pontiac GTO Forum
Anybody out there have a 1964 -1965 casting date 65 GTO WS coded engine/block their interested in parting with? Thanks,Kevinby Kevin Black - Pontiac GTO Forum
Hello,can you e-mail me the wheel codes located by the valve stem holes on your rally two wheels if you still have them.Thanks,Kevinby Kevin Black - Pontiac GTO Forum