Hey dudes,just changed my intake gaskets on my 327,put Fel-pro 1205 gaskets on...perma-torque were on there! Engine is equiped with a weind single plane Xcellerater aluminum intake,edelbrock 750 performer carb,1" open spacer,stock HEI distributer & coil,accel super stock wires,auto-lite plugs,camel hump heads,forged pistons,stock rods,crank,melling HV oil pump,headers,160degree stat,crane RV cam. Engine is .60 over and has around 20,000 on it......ANYWAYS.....on with what it is doing. Today I went to the store and it was running great until I started cruising aroung 2,500rpm and it started going crazy on the tach. As it was doing that I heard what sounded like a miss in the exhaust or small pops (like it was running out of gas) . But,when I punched it up to around 3000rpm and above....ITS was GREAT!! ... and when I'm cruising at 2000-2200rpm,its fine. It only does this at 2500-2800RPM ....what could my problems be?!?!?? checked the intake for vaccum leaks..didnt find any,carb...none. I dont know. timing seems to be right on.. HELP.