Originally Posted by formula69

HEADS/CAM WORK:
Lt1s respond very well to even slight changes in the cylinder heads. anything from a freshen up (3-4 angle valve job, pocket port) to a full out port of the stock heads will net you great gains if matched correctly with a cam. up the lift with some 1.6 rockers and your set. i know people who have got these motors in the upward range of 7k rpms. as for aftermarket heads, afr makes some good deals ranging from like 185cfm to 225-230, also edelbrock, trickflow, and the all popular LT4 heads are available. As for cams, the most popular off the shelf cams are the lt4 hotcam and cc305 (pretty mild) to the cc306 and GM847 (heafty) a few guys like joe overton and lloyd elliot make customs that are pretty stout.