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Author Topic:   Plug gap w/ MSD 6T
posted May 12, 2003 06:42 PM
We've been running a .35 gap on a J4C plug (double hump heads) for several years but recently we started to wonder if it would help to open this gap more. Using a MSD 6T & distributor - no alternator. Will we get a better burn? We've seen the adds for the HEI ignitions that advertise a .75 gap and that's what got us thinking about this. Can't find anywhere where MSD addresses plug gaps.

old racer
posted May 12, 2003 07:10 PM
We've done some testing with this on the dyno. There was no real gains after .045 with Performance distributor with 16 volt battery. The more gap does put more load on the coil and can make the car difficult to start. I stay .040 with MSD or HEI and have no problems. This was a decent 13 to 1, 355 with iron eagle heads. I use the Autolite 132 racing plugs or the autolite 25 or 26 when we can't find the race plugs.
good luck