220BR

I picked up my 383 long block on Wednesday and will hopefully fire it up this weekend. Here are some of the details: original Merc 5.7L heads (non-vortec) rebuilt with 2.20/1.6 valves, 74.5cc, SCR=9.8, slightly stronger than stock cam (.449/.456 @ 212/218), NA(Q-jet).

So, I have two questions for you gurus:

First, what ignition module should I run for 91 gas? I have a V-22A and V-24 thunderbolt IV advance module. If I set the V-22A at 32* at 3000 rpm, I will have 16* initial and 38* total at 4400 rpm. I'm leaning toward the V-24 set at 32* at 3000, which will produce 12* initial and 36* total at 3700 rpm

Second, what spark plugs would you recommend?

Thanks for the help.

Vinny P

I would go with the V-24 module. But with that compression, I would bring the timing to 34* total. 36* may cause some detonation at times. I don't have any plug recommendations.

220BR

Thanks, good advice on detonation. I think start at 30* at 3000 using the V-24