jim what spark plug gap are you running
I'd follow MSD's recommendations with the use of nitrous. You may get more KV with a larger gap but maybe nitrous might blow the flame if its too large.
You using a resistor plug??
I've literally seen MSD coils and other brand coils go to shi! and loose KV potential for no apparent reason. Infact my friend with a SVO turbo mustang had his MSD coil go weak and its only 1.5yrs old.
Magneto will provide all the KV but if you cant get one I'd look into a non resistive plug, change of wire set, swapping to a new identical coil (nothing wrong with redundancy). I'd also double check gnd on the msd unit and chassis ground to the battery. You've probably thought this but sometimes someone elses brainstorming will support your ideas too.
The MSD will already juice up the primary voltages so I think the voltage from the Primary cct to the secondary cct will be a likely cause of shi!!y KV output.
Get your shi! sorted out for the DVKK drag day!!
Alan always good to get more input when you get in a jam !!!!
plugs are d8ea gapped at .025
was at mission on friday for testing of the larger shot
initail test on the return road left me shaking , first and 2nd gear pulled like mad!!!
but on the track thats all i got .1st and 2nd gear were strong and 3rd and 4th was like nobody was home,looks like i have maxed out my ignition and it is not firing under heavy cylinder pressure.
would like to replace the leads and coil to start but will have to see what is available on short notice.
thats racing .
p.s have mastered the art of the burn out,got so much grip i'm not sure what to do with it