I am almost 100% sure my top end/midrange miss and bottom end stumble is my opti. Changed plugs and wires a few times, no difference. Changed coil, no difference. My car feels like its running slower then it should be, any clue on how much power a bad opti can rob? Thanks.

 

All of it.

Mine robbed it all twice.

 

sounds like the opti. I just chaged mine and it fixed everything

 

I dyno'd 208RWHP and 263RWTQ today with a bad opti, and overheating.

 

I know. Mine is running really bad when warm, stumbles big time at low RPM, exhaust sounds akward ALL the time, and at WOT I think its pulling timing plus it misses bad at 4500-5000. I want to go with vented opti, but I hear I need a new timing chain and cam (plus timing cover, wiring harness), and I don't feel like changing all that now. I just spent some money on a set of Victor Junior heads, solid roller cam, and a few other things for my '88! The solid roller was gonna go into the LT1, but I decided that the carb would be easier to tune, and the LT1 should get a hyd. roller cam (like cc306) next year.