1) Is there anything on an 89 Colt GT worth keeping?

2) What is a 4G15?

3) What are all the differences between a 4G63 NT and Turbo? I know pistons and cams arent the same.. and the turbo ones have SS valves. What about the rods? Cranks are the same right? How about the blocks? How does the water and oil for the turbo drain back? On dodge blocks I would have to drill a few holes for the returns if using a N/A block for a turbo application. Are the intake manifolds different? Basically would it be worth grabbing an entire NT engine to make it turbo? Thanks everyone!!!