Looking (and only looking since my wallet is empty) at improving my top speed and gas milage (1968 C-10, 250 Cid, 4spd, 6-bolt pattern, pulling 2700-2800 RPMs @ 60mph). I believe (not sure) my rearend is geared at 4:10. I talked to Randy's Ring and Pinion up in Seattle who suggested either a 3:72 , or 3:42 but the 3:42 needs a new pumkin. At $900+ for the new upgrade/swap (includes Limited slip) is there a specific donor car I should look for?
