Suprise 1/4 mi from my SC

I got 2 SC's and one of them is a 90 Auto with 280k miles on it with no rebuild and has serious blowby out the oil filler since the previous owner blew the head gasket. I replaced the gasket and it still has bad blowby so i know the motor has seen better days. Anyways it got 4.10s, dual exhaust no cats, shift kit, cold air 70mm MAF, and IC fan. Thats all i know as some of the mods were put on by previous owner so i don't know of any engine mods. With all the smoking from the engine and it running like crap it ran this

60ft 2.2
330ft. 6.4
1/8et. 9.9
1/8mph. 70.3
1000et. 12.9
1000mph. 81.1
1/4et. 15.33
1/4mph. 89.2

Now this don't seem right considering how bad the engine smokes and has bad O2 sensors and runs very rich with a bad idle. What's goin on?

Sounds about right to me with the 4.10 gears in. Any overdrive on the supercharger ? Has the resonator in the exhaust been replaced ?

It just got stock pulleys and dual in and single out magnaflow with no cats and thats it. I just got a 90 5spd SC with the same mods except it got 2.73's gonna take it to the track soon as i get the clutch put in. I wonder what it will run.

I'm guessing it'll run a little slower just because 5 speeds are trickier at the track