MSD is working
 

Stepped up 350 vortec ported and 4bbl roch
I finally got this MSD to work after replacing the box. It now runs well but advanced timing difficult with my light as it seems to bounce around a bit. Throttle response nice. Tbolt V just as good however. I wish I would have known this before I purchased a nonrefundable electronic product.

Suggestions on springs and bushing - currently 2 light blue springs and black bushing. Engine run at 5280 feet above sea level.