the 4.3's have the same bolt pattern as small blocks thats why you can never find 5spd's in s10's @ the junk yard there all T5's. If your not worried about emissions, Edelbrock makes a carbd intake manifold for the 4.3's and 300Hp would not be that difficult to make. With the typoon manifolds you could turbo it fairly easy. I agree 3.8 should have replaced 2.8 and 4.3 should have been offered. I am pretty sure 4.3 has the same motor mount as small block. Gut the electrical and run a carb (sorry i'm kinda old school) the easiest swap for trannys would be a TH350 but you will need the torque arm adapter from B&M 79.95 from summit and a driveline from an 80/81. Everything else is fairly simple, stock shifter will work just not 1rst positon, 2 is 1, 3 is 2 and 4/D is 3rd. You will also need a fuel press reg if you want to use the in tank pump. hard part of swap will be rewiring pump, gauges, dist and lights but if you know anything about electrical work it will be cake.
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