I blew the original motor after about 15K running with the blower. See my Sig., I got a still in the crate Cobra Shortblock, And all OEM Cobra internals. In other words, everthing that should be Forged is Forged. With the 417rwhp I have figures out to be 490hp at the motor. ( 490 X .85 = 416.5. ) I took the standard 15% parasitic loss number. It ran me about 7K, some of you may think that is high, but there was a lot of labor involved, not to mention re-installing the SuperCharger. And I didn't mind paying so much, I had just retired and pulled 10K from my 401k. *****, after 25 rears on the job, the 10K didn't even make a dent into my 401k. It was like found money. Get a used Cobra Shortblock (good luck!) and forged rotating assembly, you shouldn't bust anything with this. I know longer fear breaking anything, and I too will be shooting for 500rwhp. You, and me, will be close to 600hp at the motor. Now that's a nice number.