Sherpa, Mike (good guy) knows his stuff... he dropped the 4.3L in my '89. I stepped up to a 9 lb. pulley so to be safe I run high octane and a bottle of octane boost to boot. In pings a little if I put my foot in it at low rmps (<2500). Shifting it between 3500-4500, with 4.88s & 35" it cruses around 70 mph at 3000 rpms. If I'd stop winding it up just to hear the whine of the blower I'm sure I'd get better milage. <img src="/forums/images/graemlins/lol.gif" alt="" /> I'll check out your buddy's CO page, I'm always amazed every time I wheel here. Take care.