This may have been answered already. Please forgive me if it has. I have a very tired 89 comanche. I'm moving from a 2.5L to a 5.3L LS. I can't see paying the 6 Bill's for Novak's radiator solution since the 5.3 will remain mostly stock, and will have twice the HP anyway. However I noticed that even among the "performance" radiators there is a difference in price where the ones for the 90 and older are almost double the 91 and newers. Can anyone tell me the difference? They look almost identical from photos.