[MAStuart]

Joel Tune will be way different! Any idea what cam you are thinking about for the 347? Are you planning to use your same intake? Will it support more HP or is it restricting the power you have now. Injector sizing and mass flow?

Get what you have apart. I dough you drove it 60 plus miles with a spun rod or main bearing. Might be a very minor problem. If it has a bad bearing a set of bearings and a crank grind or polish might take of it.

As far as highway RPM's . Is your Richmond gear trans a non overdrive 5 speed? I so you must be running low rear gears with shorter rear tires. That combo needs a high rpm motor to use first and second gear . Change the rear gear to a 3.25 with some taller rear tires and your highway rpm's will be lower. That combo will still take off like a car with 4.11 and a close ratio 4 speed.