Thunderbolt 5 Ignition Q's?

[C.Fisher]

We are running two 454's with Holley 250 s,chargers 5#s boost. The ignition from what we can tell is Mercruiser Thunderbolt 5 dizzys. Originally we think this boat was fuel injected 300hp 454's. But someone switched them to carb blower motors that have had a host of problems that we are now sorting out. For instance we are getting 40 degrees advance with 8 degrees intial timing. We need to back this off to no more than 30-33 cause of the blowers. What can we do with these dizzys aside from swithcing out to MSD products.
From what I read in a mercruiser manual these dizzys have knock sensors and modules but how in the hell do those work since there is no computer for fuel injection any more. I am lost so please help. I have searched and did not really come up with many answers. Boat is a 2001 checkmate convincor.
Thanks in advance

[DEL51]

Have you tried to check with mercruiser? A Knock sensor affects timing.I hope you can get some answers!

[C.Fisher]

Ok after some checking I found out that Crane makes a HI-6 ignition box that will utilize the TBOLT 5 dizzy but will eliminate the control module. The cool thing with the Crane piece is that it comes pre-programmed with 7 different styles of advance curves that are based off of mercruisers engine lines including the supercharged line up, also they are pretty much designed to be plug and play into the factory wire harness. Priced threw jegs it is about 300.00 and here is the link to crane pdf. spec sheet http://www.cranecams.com/pdf/90006462b.pdf
From what I did read on the net is that some of the modules will start shutting the engines down @ 4600 rpm, if this is true that will explane why we can only rev that high then the engines fall off.
We will pick these up then I will post the results we get.
Thanks
Chad Fisher