Quote Originally Posted by tayto
Fast, do you recommend a .035" gap on a 10:1 vortec headed TBI 355? I was told to gap them around .045-.055"... Have a brand new AC Delco coil, was told not to go with a MSD. Got the engine running on R44LTS and have a set of R42LTS that will be going in.
.035" would be the ideal gap on that engine. I prefer not to go much wider than that on most applications. I've heard both ways on aftermarket "performance" coils, but I've never seen any hard evidence for either argument. I've run MSD and Accel coils on TBI vehicles with no problems, but I couldn't say that they performed any different than the OE coil. That being said, the OE coil is just fine for your engine.