Prater

Is anyone running an MSD 7ML-2 or 7AL-2? I have MSD rev control already but they are not the marine version. I have considered adding the 6M-2 and changing to marine rev control but can get the 7AL-2 for the same price as the combined marine ignition and rev control, but only have one box to mount and wire up. This would be added to the Mercruiser Thunderbolt Ignition already in place. Twin Big block application with 177 Blowers.

Big Block Billy

Whatever you do, keep the t-bolt distributors. The Msd ones are not made good enough for a boat. My friend had 2 of them and they literally came apart.
I can't understand why they couldn't design them with an electronic advance like a T-bolt.
My friend is running the Marine Msd boxes. We actually picked up speed and RPMs when we went back to the T-bolt IV's.
The marine boxes are more vibration resistant than thier automotive counterpart.
But because of the special potting compound in them they are less servicable than the automotive ones.
When they go bad they are basically.... Bricks !

mopower

I'm glad you said "when" and not "if"

jeff1000man

Use MS-6's. I havn't had problems with the MSD Marine Distributors yet. Use the stiffest springs they come with.

Big Block Billy

Yeah but , the spot welded parts of the mechanical advance should be brazed or welded for any durability .
They were the real flimsy part and spotwelds broke on my friends units. Shame on MSD....
The boxes stop Msd'ing at 3000 Rpm's too.
The best thing I've seen with them is a clean transom !
Money is better spent elsewhere , like on BEER !

jeff1000man

I'll look at those before I get to many hours on them. Thanks for the heads up.

[email protected]

6m2s w/ the soft touches work great but dont seem to last to long. ive been through 3 in 6 yrs. If you send them back they keep them for about 6 months then tell you they cant fix them. I guess i better take a look at my dists too!

Prater

Thanks for the info, I will stay with the Thunderbolt and just keep the rev control boxes in place.