Welcome to Forever Pontiac, full of great ideas for Pontiac performance, maintenance, or for peer-to-peer assistance from Professional and DIY mechanics. Also, compete in our Pontiac monthly competitions. Please register if you'd like to take part.
In here you can post questions and concerns that you have about your Pontiac and have them answered by our knowledgeable members. Also you can post part numbers, old recall bulletins and stuff of alike.
Welcome 1977GPX! The 988 most likely has xx in front of the whole pn# which is 481988 which was the resurrected 400 block from 1971-1974 (much stronger block) the block was resurrected in 1978 and part of 1979 for the 6.6 Firebird. So they gave it the casting number xx481988.