Is there any general rule of thumb for amount of retard? Is the rate of retard controlled by rpm or boost? May be there are instruction with the msd unit But I doubt that for obvious reasons. I have a turbo from a cummins and have an m-90 sitting on the shelf just begging to be used.The problem I see is my compression is to hi to run gas( I think ). I`d have to change cams because I`m only running 109 lobe separation and I think to much boost will be wasted. Last is I`d have to figure how to extend the blower snout.
