I have a 1983 K20 4x4 with a stock 350. I'm looking at upgrading to either a newer 6.0 or a 6 gen 454. Also what do you guys think I should do with the transmission A/T or M/T? I'm new to Chevy but have been working on Toyota's trucks for years. Also if anyone has done any one of the conversions what should I know about do a project like this before I start.