[Hammer49]

I have a 68 350cid Bored 30 over with a mild comp cams {#12-238-2}.And Double bump heads redone with stainless valves.Iam running the stock plugs with a MSD 6AL and AC R44 with a gap of .035.Is this the right setup,or do i need different plugs and a bigger gap for the MSD unit.

[HarleyD67]

The plug gap is a little small for that mild of a motor. I would run @ 0.045"-0.050". In fact when I first started running MSD ignitions. It was a 6al box with a pro-billet dist. an a 350 built up not much more than yours, and I ran a 0.045" plug gap for 3 yrs. I think the example from MSD below is a little wide in my opinion.

These examples are just starting points to get you going in the right direction. Every application is different and should be tested and tuned.

[Hammer49]

So what plugs do you recommend to run .Can I open the gap that much on these [R43] plugs that are suppose to be gapped at .035 .

[DOUG G]

I have the 6al and HEI. I went to .060 with my r45ts and had no isues with the plugs. Since then I've dropped back to .050 and see no changes.

At .035 do you still run points ? I would say .040 - .050 should be fine.

[Hammer49]

So Can Anyone tell me whats the ADVANTAGE of a bigger spark plug gap as apposed to the stock gap.

[DOUG G]

bigger gap equals hotter spark.... but at the cost of plugs,wires,and/or ignition parts.(coil mainly)

[Hammer49]

So do i really need to gap my plugs bigger or with my setup leave them at .035

Thanks

[HarleyD67]

No you don't need to, but you would pick up a little performance with it. Like I said don't go extreme with the gap 0.055"-0.060". This will make the ignition system work too hard.(shorten parts life) I would open it up a little more to 0.045". This will give you some performance gain without having to worry about excessive where and tear.

[Hammer49]

Thanks for the advice.