[blykins]

Rotational velocity I'm not worried about. From an engineer's point of view, it's a fatigue cycle. A piston trying to drive the crank through the bottom of the engine 4000 times a minute is less harsh than one trying to drive the crank through the bottom 6500 times a minute.....you had it with the loading/unloading you were describing. Two bolts/studs sunk through a bearing saddle and a main cap is all that's keeping it from coming out. What's the fatigue stress of an ARP main stud? What's its natural frequency?

Usually at those rpm's you're at wide open throttle also....so you're not cutting it any slack.

Regarding everything else, I was worried about a 2-bolt main block taking lots and lots of stress.

And yes, the extra $3k would break me. Considering the car is about 70% finished, I just finished building a 425ci SBF, and now I'm starting another engine build. I can't afford the extra $3k for a shiny new block like some other people can.

Thanks for the input guys....

Onto the next step.