1989 NA high rpm stumble
 

I have a 1989 NA vert with 126000.

It smokes when you hold the idle at 4000 rpm for more than 30 seconds so I know the oil control seals are on their way out. Shifting above 5500 rpm causes a puff of smoke as well. Lately the car will not rev past ~6800 rpm and starts smoking as well. It stutters and stumbles at this rpm but will rev smoothly until then. Sometimes if you floor it it almost sounds like it is pinging. I have checked the timing and the TPS and they both seem okay. The car has RP reduced ratio pulleys on it and the timing marks are not in color. They have been set at the third pin leading and well behind the last pin trailing.
Is it possible the oil getting past the seals is causing it to "miss" at high rpm? I have new NGK plugs(~1000 miles). Could it be the jacobs ignition?

Thanks,
David

My engine mods are

Bonez cone filter intake
RB street header wrapped with heat temp tape
Bonez highflow cat
60mm HKS exhaust
Jacobs ignition box
10mm magnacor wires
Reduced ratio pulleys
New NGK plugs
Lightweight flywheel