Most of the fast Shelby boys run tony Otto 331's
With approx 500 hp and 500 lbs of torque they spin them to
7000 or 7200. You need to change the springs almost every year
if you track a lot and spin it,,,
347 out of a 302 not good. Piston wrist pin hangs half way out
Of the cylinder on the down stroke ... will rock and break things
If you want to rev it. 6000 max with a 347 to make it live
I know as I scattered one on front straight of thunderhill
I agree with Weld (can't believe I am saying that

There is nothing like a high spinning stroker singing in your ear
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