this is a dumb question but my boss told me my car should have posi-traction, but when the tires burn only one spins. should a '79 zx have posi-traction?

No. There were no 280ZX's that had a 'Limited Slip Differential'.

These only became standard on the 1987.5 300ZX Turbo's.

Actually I have the original R200 in my Z and when I put it on the rack in gear while on both wheels did spin.. And when I do burn outs there are two marks.. :hpydance:

Then your R200 is not original or it was modified to be an LSD unit. The fact is that Nissan didn't even make an LSD unit back then for the Z-car.

Now I pose this question to you all:

Does any reputable company make solid carriers for R200 diffs? Maybe spools? I'm thinking this would be a more affordable approach to locking the rears on my Z compared to a 300ZX LSD.
On the same note, if I were to have a carrier custom milled, what should it be made from, and about what do you suppose this would cost?

Comments and questions appreciated in advance.
-Dave-O

Even if you pay $500 for a 300ZX unit (used) or $700-900 for an aftermarket LSD swap, I dont' think a custom made solid axel locker is going to beat those prices.

solid axle? dont you want IRS? or is all this effort in search of the easiest way to smoke your rubber? i too leave 2 trails of rubber, and have the original diff. but then again, i have always felt more power coming from the right then left or so it would seem.
????

Well, it is common knowledge to say even with an open diff, with enough power, both wheels will spin. I simply want to lock the two rear tires to the same speed, as my Z will be mainly used in competition drift events. If I do drive on the street, I'll be getting sideways anyway.

My stock diff was acting up anyway, last time I drove her. I'm just looking for options that DONT include welding the spider gears.