bolt ons
The best bolt on for the carbed motors is headers of course. Poston's headers for the 84-85 non-intercooled GN's. are a direct bolton. I have a 78 Lesabre TC that I eventually converted to the 84-85 SFI setup. You could call that a bolt-on although a pretty serious and time consuming one it was. Oh and pull out the Turbo350 and the 3.08 gears in the rearend. Put in a 200-4R and a set of 3.73's. The tranny is probably the next easiest upgrade,the only thing necessary for swap is the crossmember from any 81 or newer full size GM car that had the 200-4R. If you don't know how to setup rearend gears have a shop do it. You can get a set of used 3.73's from any full size Chevy 1/2 ton with the 8.5 inch 10 bolt rear. If you're trying to find them in the local salvage yard youself, look on the glovbox for the option code sheet, I believe the code for 3.73 gears is GT4. you may want to ask a guy at the Chevy Dealer if that's correct. That'll save you from getting dirty before finding the right ones. Give your local 4-wheeler shop a call, he may have a used set. yes the gears will work on your posi carrier. Any questions, feel free to e-mail me or call and we'll chat. 763-783-0700 Brad