After the s10 cylinders and long shoes,you will probably be leaving the line at about 10 lbs of boost, and lack of traction may become a problem at that point, so as you said suspension upgrades would be a good next step.
You could also remove the front sway bar and do the 90/10 shocks for some weight loss and better weight transfer,along with relocating the battery to the trunk, though these may affect some street handling,and the upgraded rear brakes could also get a bit grabby in wet conditions, so in the quest for better 60's your car may start to get a bit less street friendly ,it all just depends how far you want to go,but these mods are all cheap and easily reversible,if need be.
Also your car being a gn has about a 50/50 chance of having the steel bumper supports instead of the aluminum,have you checked yet to see if you have the aluminum ? vd6 and vd7 are the codes for them on your rpo code tag.
You can also get brackets to completely remove the bumper support if you choose to.
These suggestions are mostly geared towards free or inexpensive mods to help improve your already not too bad 60 ft times (for your combo),which will also lower your et.
