Reply With QuoteI guess it will be one of those lets drop it in and find outtype of things...
I have been researching this ignition swap for the last little bit with no definate answers other than putting Thunderbolt V6 modules on Big blocks to advane timing. Since I have found ***boat.com to be the best resource for Thunderbolt information I thought I would post here, Thanks in advance.
My Saltwater boat is an old 22' Sea Ray that came with a Merc 228/305ci chevy motor. It has points and condensor which I am looking to swap out. I have a parts motor in my shop from my Dad's Sea Ray which is a 1987 7.4L Merc that came with a thunderbolt IV ignition. I know the distibutor would be a straight drop in but I was wondering if I could use the existing module (the one attached to the exhaust riser on the 7.4L) or would I have to get a new module for a 305/5.0L. I am planning to do this in conjunction with a Vortec head / Edelbrock intake manifold swap as I have both sitting in my shop as well. If I could get away with this, the thunderbolt would be the right price. If not I'll probably go with a Pertronix conversion in the stock distributor.
I would have dropped in the 454 in true ***boat fashion, but the Alpha drive would definately not have survived for long.... well at least it hasn't in the past
I guess it will be one of those lets drop it in and find outtype of things...
Well I feel not so swift :idea: as I have found the answer in the Mercruiser Service Manual sitting on my shelf, same advance curve for all GM V8 motors with the Thunderbolt IV maybe except the 5.7L Ski inboard but it looks the same as well. I figure I would post in case anybody is looking for the answer in the future.
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