I have a '85 monte carlo 4.3L v6 all original. My goal here it to upgrade the engine newer, more performance? any suggestion?

 

First off it depends how much $$$ your willing to invest and time. But a 350 or 383 are inexpensive and you can get quality performance&parts just about anywhere . Decent cam,headers,carb and good exhaust system for starters

 

If you are interested in keeping the 4.3 there is a couple of companies that make a turbo and intercooler for that engine. Remember the GMC Syclone/Typhoon.