The car and motor are in the sig. I have just purchased an MSD 6a ignition, and I already have the blaster coil. I currently have NGK TR6s in it. I am battling some problems with cutting out at the upper rpm band, and thought maybe a stronger spark would help. Right now they are gapped at .035". I just installed the ignition box and am having the same problem, and now am worried it might be detonation or something else besides weak spark. What gap should I have my plugs at with the stronger ignition? Also, anyone else running a similar high-compression setup on 91 octane pump gas. 93 is not available in my area.

 

I have 11.5:1 CR on my 383 and I use .040" TR6's without a problem and with STOCK ignition. I've had issues with MSD products ESPECIALLY the Blaster coil. Seen them go bad really fast.

I'd try putting the stock coil back on, checking for arcing at night on the wires and at the coil.

Also, what lifters are you using and how did you adjust them?

 

I had the stock coil in there for a while and it was even worse. I replaced it with the MSD coil and it got a lot better, but it still misses higher in the rpm range about 5k and up. On the previous coil it was about 3500 and up. I am still running the stock lifters ( although they are new), and I adjusted them a half turn past zero lash. (intake closed adjust exhaust, exhaust opening adjust intake)

 

Did you install a new opti with a opti wiring harness?

Do you have DataMaster and if so, have you logged it?