Z26 is just a body style and slight suspension upgrades...They were only made after 92 and just had a plane jane 3100 in them. The did look significantly better than the stock model though. As far as performance wise, the GTZ's were the good ones and those came with the HO Quad 4. I am happy with my 91 Gt though. It's got the older 3.1L in it but with the suspension upgrades, is fun in the corners and also isn't doin too bad on torque although hp numbers are pretty dissapointing. All said and done, there really isn't much difference between my 91 Gt and a 91 Cavi with a V6. Most of the drivetrain and suspension parts are actually interchangable. The bad side is there is very little aftermarket or following for the retta's, much less than even the Cavi's.