Don I had a 86 Buick GN. With aftermarket bolt ons turbo,chip,intercooler,exaust,fuel system,cam,heads etc..... it was pushing 425hp. I tell you what though the 2 bolt mains needed a girdle for flex and it went through rod bearings on occasion. With a high stall converter that thing would hook up and run away. I never ever had so much fun with a V6 in my life. Being used to the old Ford big blocks this was a new adventure for me. I bought the car stock did a few upgrades at a time. It's an expensive toy as they all are. ATR had the best parts though Poston and Kirbans were a close second. It outran almost everything at the time. Vettes no problem.Took a while to learn how make it handle with the box body and automatic and all. Dam t-tops flexed and cracked the roof even with all the support braces in place. It loved CAM2 with a heated O2 sensor. Man that car was quick!!! I never did figure the MPG's and did not really care. The coilpack ignition system was a no brainer and overall the car was very dependable and street manners were good. From what I understand the 4.3 blocks were a little better than the 3.8's but never got that far. What a fun car and the only thing better was the GNX. G.