How Much Horspower can a stock lower unit take. I have ported & polished heads with low compression and Iam adding an ATI blower #7-8. Iam guessing that this combo will put me at or very close to 600rwp. But can the stock piston and crank take that much power?

 

IKE, maybe if you have it tune properly Harlan Made 576rwh at 12 psi and his engine held pretty well.
most people say that the stock is good for 500rwh though.

 

I made a lot of runs (18 runs) on 600 to 656 RWHP but I did go lean on nitrous and blow up.. I was really amazed at how well the stock stuff held up.. 500 to 540 seemed a lot easier to tune for though..