I don't doubt the advice. However, I see several examples of people running the original pistons and making power that I could be quite satisfied with. In fact, I'd be concerned if I take the power level much beyond the 400 at the flywheel ballpark, especially with a 4 speed, I may be breaking things.
Hard to draw the line but the original intent was to emulate what has been proven with the junkard 360 article and those who ran with the idea. As far as internal balance, I already invested in the spendy 360 Magnum flywheel when a discount came available. It's the old catch 22 - gather parts when the deals come around - then the plan changes... :banghead:
If the engine needs boring then the decision will be made for me. Until that is determined, I'm interested to know what a safe limit for the camshaft might be with stock pistons.
(I know anything I do will need to be checked for clearance after install).