Ok so finally got a chance to put the 350 in. I replaced the chip with 350 specific one. I had to get it out of the shop so havn't had time to put it on the scanner or datalog!! Im just wondering why I get a real bad stumble just off idle if I put the foot down hard, or more than half way??? Its a basically stock 350 with 462 heads/comp 260h cam and headers and an afpr. With ultimate tbi mods. I also had to advance the timing a fair amount to get it to run decent. I know that I need to datalog and do some tuning but any thoughts would really be apprecaited!!! Thanks again Just wondering If you think its fuel or timing related?? Please give me a little help