my name is sean, i have a 91 civic si hb and im turbo charging it and have no idea what radiator to use since my IC pipes have to run right where the factory radiator is, i know i have to get a smaller radiator just dont know which 1. also need to find a oil return line for the turbo which look to be an older style mitsu GST or GSX turbo, the turbo i have is a TD40 is very small and has no threading for the return line looks like the plate hard line style.

 

You might get a better response if you put this in the nitrous, supercharger, turbo section. I have no clue.