Dang man !!..i threw all the know how at this situation....the only thing left to try is some different starters...i would do just as you said..i would go to NAPA and talk them into letting you take one of their starters to bolt up..you may want to explore the off-set bolt pattern...the one they use on the newer corvette is the one we use on my wifes 400...it has good power etc...
Please let me know when you find this out...i would like to know the answer here...
thanks and good luck- Brian
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Bjuice..
"I'M YOUR HUCKLEBERRY ! "