I'm swapping on a pair of fast burn oval port heads with 100cc chambers (GM19256821) onto an '87 Mercruiser 454 that's probably .030 over. They will ported and flow very well for an iron oval port. I'm also swapping to an ISKY cam that's 236/[email protected] on a 114LC. The fast burn chambers are timing sensitive and do not require more than about 28* of timing total. With my current Thunderbolt IV that gives 24* advance isn't going to cut it. No way it'll idle decent with only 4* base setting. The V6 module would probably work OK if they were available.

I've seen adds where a Thunderbolt V module could be used with an adaptor, but never any actually for sale with said adaptor. If someone has a diagram, I could build an adaptor harness.

Then there are the Delco EST distributor and marine module. What's the consensus on those units? Supposedly they were available on 1990's vehicles and would just need the purchase of a marine module.

This is a budget build, so I really don't want to shell out for a Daytona, or even a MSD for that matter. Or do I not have much choice? Ultimately, I'd like to have 12-16* initial with 16-12* of advance added. Any experienced input will be greatly appreciated.

For those wondering, I've picked up a no name oval port air gap dual plane intake for less than $100 brand new. On a similar build there was a mere 5hp difference between it and an RPM air gap. I'll initially use my existing QJ with an adaptor and then move up to a larger Holley adapted for marine use.

i run a ton of est,s....... set your top end timing and it will idle in the high teens and all parts are cheap and easily available i even bought a few 40 dollar temu ones and they are the exact same as many other brands they work well i thought they would be junk it also retards the timing bellow 400 rpm to get it started

The V6 module will give 6-10* of advance on a V8 engine with full advance by 2000rpms
The V8HP module gives 20* advance with full advance at 3000rpms.
There are prob some used ones out there to be had.