my car seems to misfire in 4th and 5th gear...the shop put a brand new set of plugs not sure whats the gap but that didnt fix it..i tried coils and wires still didnt fix the problem...also checked the egr lines those are all plugged...should i try re gap my plugs ? im making 340 on stock 8 tubo what should i gap it to with ngks ?

 

.020-.025.

 

I just had a similar issue, try re gapping the plugs, its easy enough.

gapped mine at .020 for e85