So my brother has an '86 Trans Am 305 TPI with an HEI supercoil, K&N Air Filter, and a borla muffler.

I have an '86 Iroc with the same 305 TPI. I just rebuilt the top half of my motor, new fuel injectors, new vacuum system, new harmonic balancer, sensors, etc. I am running hedman shortys with a y-pipe, no cat, and a flowmaster muffler (all this work done in the last year).

Both cars have over 100k, eliminated A/C and eliminated all emissions. We constantly mess around with each other but haven't gotten around to a straight, actual race. Who do you think would win?

 

proli yours cuz of the mods

 

Is his a 5 speed? If so, he might be able to edge you out.

 

IF the miles, wear, etc. are roughly the same (100k & 160k aren't quite the same), I'd say yours too, based on your exhaust & new top end (&injectors). Older injectors can get bad flow..

 

Both autos. I forgot to mention, he's got 55 width Z-rated tires on his GTA rims. I've just got some 50 width radial TAs on my stock megs. His car gives a puff of white smoke at startup, though, due to his tired heads lol. I just cleaned, wirebrushed my valves, and put new o-rings in my heads and I'm glad I won't be having that problem any time soon.

 

How close is the actual Mileage? If they are close, the race should be pretty close depending on the drivers.

 

Iroc has about 110,000
Trans Am has about 130,000

 

You should probably get him by a car or so, give or take. If they have the same rear gears.