I have a '86 as well and had a very hard time getting the weight off. I was about 60 lbs over even without any interior or door glass. I had cut the dash down a bit and removed all the hvac stuff, as well as windshield wipers, headlights, and anything street related and was still heavy. I weigh 160 race ready so nothing I could lose there. This last winter I got more serious and cut out most anything I didn't need, including gutting the doors down to just shells, minimal dash, lexan windshield, miscellaneous wiring and any bracket not needed. With 6 gallons of gas, a fire extinguisher and fire system, and no coolshirt cooler I am 8 lbs under. Now I can run ballast of steel plates weighing 2lbs each I stack in the passenger footwell.
Having said all that, one of our guys, Sid, drove his full street legal car weighing I think 2900lbs race ready and him and I would have great battles, usually with him beating me.
If you come west and race with us in Nor Cal, and we'd love to have you, I don't think it will make much difference at Thunderhill, and only slightly at Infineon. with it's hills and quick direction changes.