not usually true. many cam only and head/cam cars run 125-150 shot all the time. 150 shot usually takes it toll on the stock shortblock, but i've seen many high mileage h/c and cam only motors take 100-125 shot equalling 480+ rwhp and live a lnog time. In fact, i've never seen or heard of anybody around here blow up a stock shortblock on anything less than a 150 shot. i've seen a few go on a 150 shot, but thats all. There was a guy who had a 116k mile stock shortblock that he had lt4 heads, hotcam, and a 6 psi voretech kit. He never had it dynoed, but it trapped 120 easy at the track. i believe he ran that setup for over 7 years without a problem. hotrod power tours and all. he just recently pulled the motor in favor of more boost, but he never had a problem with his old setup on a stock shortblock.

 

As a few others have said KEEP IT FUELED and it should be fine providing it is in good shape. There are more than a couple stock shortblocks surviving at that power level.

 

Did you mean to 403rwhp NA AND A 250 SHOT on a basically stock shortblock. That's awesome that it can handle that, I pretty much got the same setup with clevite H bearing all around, a moroso HV oil pump minus the forged pistons, i'm looking at running 150 shot on top of a 224/224 cam, If all goes well maybe I should bump that up to a 200 shot (whats nice with this small cam is I won't need to wind out the motor nearly as much as a bigger cam).