The problem is your jumper cables, they are junk. It looks like about a 10 gauge wire. Too much resistance, too much voltage drop. Go back to the original starter that fits, use some real battery cables of at least 4 gauge, or even 2 gauge, properly connected.


[img]http://i.imgur.com/boeexFms.jpg[/img]
31 Plymouth Coupe, 392 Hemi, T56 magnum
RS23J71
RS27J77
RP23J71
RO23J71
WM21J8A
I don't regret the things I've done. I only regret the things I didn't do.
"Wise men talk because they have something to say; fools because they have to say something. ~ Plato"