My starter went out on the gta, so I bought a GMPP mini-starter from summit and in the process of taking it out I looked at the flexplate and saw that most of the teeth on one side were all chewed up. So now I need a new flexplate but I don't know what size to get a 153 or a 168 tooth?

 

First off, if your starter can be used with the 168 tooth flywheel get it because its way easier to find[ for future reference], second and most important, if your engine is a one piece, or "full circle" rear main seal you have to get a balanced flexplate, 1988 should be full circle rear main. If you don't use the right flywheel it will throw your engine out of balance and wear your crank bearings out real quick, not to mention the vibration would be unbearable. the one I used in my car is TCI part# TCI399773. If your two piece rear main seal then you can use TCI399273, these are both dual bolt pattern so any converter will bolt to them, I got mine from summit racing. Hope this helps ya out

 

I might have one for ya. let me know what you need and I will check my shop.

 

Your flexplate is the 153 tooth version. If you just want a bone stock, no-frills replacement flexplate, they're dirt cheap (usually about $35-$45). An SFI approved racing style one will cost 2-3 times as much.