Hey this may or may not answer your question but I have a 92 chev with a 5.3 in it and i just bought schoenfeld headers from summit, there actually made for 88-98 trucks with ls motors but i cant imagine our trucks would be a HOLE lot different. if you wanna check them out heres the link. hope it helps!

http://www.schoenfeldheaders.com/LS1-TRUCK.htm

EDIT: and there only $250 for lt's!