How fast can you go with a Magnum? Who has the quickest setup?

So this is mostly encouraging stuff, guys.
The info is greatly appreciated...if it weren't for folks like you on this forum, my Magnum would still be on a stand in the garage. :D

IIRC, the factory fuel injection is a performance bottleneck, correct?

Have people had good luck with aftermarket EFI like the Holley Sniper, etc?