Well i have this posi laying around and i was wondering is it would fit in my 88 z28 and if so what else would be needed for the swap. Been trying to find what kind of posi and gear ratios but havnt had any luck in my search. Or am i better off buying a 93/97 diff

 

First you need to determine if you have a BW 9-bolt or a 10-bolt. If you have a BW 9-bolt axle assembly, be aware that NO 10-bolt parts are compatible. So Don't buy anything until you know what is under your car. Only advice possible with your limited info.

 

It's a 10 bolt

 

Count how many times the pinion spins to the wheel's/drum/rotor's one full turn. The number of times the pinion spins is your gear ratio. Example: a healthy 3.5 turns would be a 3.55 gear, a little less than 3.5 would be 3.42's, and so on. To know what type of center section is in there, you need to do it the hard way and pop off the cover. Then while the cover is off, you can read the gear ratio that's stamped into the end of the ring gear. Simply going by numbers off the housing may not be accurate any more, as guys have a tendency to swap gears and guts.

 

Now that you know that it is a 10-bolt. All you need to check per Camaro 69 is the ratio in the car. Since it is a 1988 model it will have 26 spline axle shafts and this will also limit your choice of limited slips carriers you can use. Not as easy as you thought.

 

im going to take the easy rout and just weld the dam thing. ill swap a rear end in it later.

 

That's fine, as long as you don't plan on making any turns.
Otherwise, be sure to carry a container with you so you can pick up the pieces of the center section or axles when it blows apart from all the extra stress it isn't designed to take.