I run the B&M Ripper but I have felt a Tri-Ax and liked it. Hammer runs one and some others do as well so they can give you the low down.
Someone will correct me here but the 98 GT's have 225hp - 10 more than the 96-97's. It's either due to a different tune on the computer or that in conjunction with a slightly different exhuast setup. I think the console is slightly different as well with a cup holder. I don't think the 98's came stock with a strut tower brace either (not sure). Other than that they are basically the same.
Someone here can verify and correct.
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66 Tahoe Turquoise Coupe
Laser Red 96GT Ragtop
Both are slow but easy on the eyes!