I have recently found some people selling a 4L60 tranny and dana 60 rear end for reasonable prices. My question is this I know both these parts are good over all but I was wondering if I would be able to install them into my 91 z28? Any information would be greatly appreciated.

4L60 = 700-R4 (same thing as what you've already got)

The Dana 60 will have to be specifically modified to fit one of these cars; can't just be a pullout from a wrecked Dodge van or something and you expect to just schklung it up into your car. If I was the betting kind, I'd bet that's all it is.

Thanks appreciate the info. Do you know any rear ends or transmissions that would actually be worth upgrading? I know I only have a 305 but I do plan on putting a 383 in the future and want something that can match that or not need crazy amounts of modifying to get that setup to work.

The only rears that will fit these cars without requiring extensive ($$$$$$) modifications to either the car or to the rear, are the ones out of these cars.

Since 4th gen ones fit right in except are 1-5/8" longer on each side, they're a good swap candidate. They're not any "stronger" than what you've got; but they are available with a vastly superior posi carrier than the Auburn POS that came in the 3rd gen 10-bolts (which most likely you don't even have that, but only an "open" one), often better gear ratios, and of course, better brakes. You have to use 4th gen or Vette wheels, which would require spacers on the front to make them fit there. Your itty-bitty 15" wheels won't fit over the modern brakes anyway so that'd be a great opportunity to upgrade, all the way around.

Any Chevy V8 700 or 4L60 trans will fit, as long as you keep your existing extension housing. Without that, there's nothing for the torque arm to attach to. But none of them are really any "better" than what you've already got, so might as well just build yours up when the time comes.

That by far is probably the best answer I've gotten from somone. Greatly appreciate it. In that case I'll just stick with what I got and go from there. Thanks you've been a great help for sure