I have run several of the H/P HEI units, remove the vac advance, use a block off and get the correct connectors and roll on....never had a failure...

I ditched the MSD Marine boxes and replaced them with these. So did a buddy of mine. We were tired of the MSD's failing. We each have 2 seasons on the cranes, and no issues yet.

http://www.summitracing.com/parts/CRN-6000-6440/

I am running a pertronix in my lt4 hot cam 350. Only reason is I needed more intial than I could get with the tbiv. Running 16 initial 32 total all in by 2700rpm. Its mechanical advance but fully adjustable on total and advance rate. It fires up and runs great to 5500+. Dont jump all over me but for a na motor the fancy options with the undependable boxes arent needed

I'm looking into replacing my second MSD marine box . I was considering going to the Crane HI-6 also. Too bad they don't still make the HI-6M anymore. Have you any concerns that the Crane boxes are not marine rated?

I have no concerns. From a durability standpoint, they are potted in epoxy, just like MSD's ''marine" boxes. From a legal standpoint, I don't see USCG approved spark plugs, spark plug wires, coils, etc. I cant see a insurance company denying a claim because you didn't have a "marine" ignition box.

I believe the guys at Dayton Sensors are the guys that made the original HI-6M. If one of my 6M's do go out I would be replacing it with theirs.

MSD stuff used to be top of the line, stuff turned right to GARBAGE, I had 3 new MSD marine boxes in a row that all had different problems, MSD did not care what so ever, before installing the 3rd one I bought a MSD tester/signal generator and found the 3rd one was junk. Had 2 MSD tbi 2 plug gm coils with major problems over time, all done with them. I bought a Crane hi6 box and it has worked flawlessly, never heard of this Daytona stuff, will be looking into it though, Smitty

I didn't realize the Crane boxes were potted. They use the same wiring as MSD, it appears the order in the plug may be different though. I heard good things about the Daytona ignition. They are twice the price and the extra features they have I don't have a need for. I spent some time with the bushings and springs in my distributor to get it working were I am very happy with it and I would rather not have to readjust it.

Pic 1 is crane, pic 2 msd, pic 3 Daytona internals.

I'm checking into this also. I found traces of detonation on my 454 with the thunder bolt running 6k on 23.5pitch 4 blade. But also at daytonas 595$ is still better than MSD's 800$ from summit?
Had to add this - that MSD box looks like crap! I guess when your name is at the top of the list you send your production elsewhere to manufacture it faster. And you wind up with waszoo assembling it after he rides his moped into the sweat shop in Mexico! Geeze.