Hey guys I haved two cars to put together and need ign box help

first car is a sbf will be a turbo street/strip s475 -s480turbo 600whp goals maybe go e85 also
not sure on engine management yet either
mega squirt or used fast classic or stock ecu and chip

second car sbf solid roller 11.1-12.1 e85 street/ strip car maybe spray small shot of n20


I already have three msd boxes I can use, and want to sell one . which should I use for which car ? I don't know a whole lot about there software. I figured the 7575 for na car but not sure if I need a 7531 , or the 6530

msd 7525 digital 7 plus has 2 step retard on dials
msd 7531 ign box
msd 6530 msd 6al2 programmable and map sensor setup

 

i would use the 7531 on the first one and 7525 on the second

 

Are those cars fuel injected or carbed?

 

I use ms3x and 6al, 800-850hp on e85, no problems

 

since you have the MS 3 X you should switch over to the coil near plug ignition system you'll have a better spark then those MSD boxes

 

Plug access is from underneath, not much room to mount coils, unless I mount out in the wheel wells, 6al got plenty of spark, using large cap pro billet as can sync, easy to phase for optimal angle under max cyl pressure