what are you talking about, yes 4g63 stuff is interchangeable, the exh cams are identical, the intakes are slightly diff.

i have no clue where a 420a came into the picture, thats a totally diff story, no stock 4g63 stuff will bolt to it.

there is alot to do if you want to turbocharge a N/A 1G but its somewhat straight forward, your better off buying a turboed 1G for the price you would pay to turbo an NA