I'll take a stab at it from a buyer perspective. Assume you're car is prepped so the shop can get right to work:
- Tubs $400, if they're available for that year Chevelle (sorry I'm a Camaro parts guy).
- Shop labor...some guys say they can do it in 32 hours. I've never seen it. Budget 48 just to be sure. Multiply by local labor rates. This should get your old tubs cut out, frame notched, decklid hinges modified/reinstalled. Also assumes you do not have any rust repairs on frame rails or outer fender wells, and no roll bar mods/rewelding.
- Trunk spackle? Not sure here, but better budget at least 10 - 15 hours incase there's any significant trunk prep involved.
Then there's wider wheels and tires if you don't already have them? Finally, count on delays and unexpected issues. It's just reality w old cars.
Good luck
