limit on 455 cast steel crank

[455GTO]

I have a 455 pontiac motor with srp forged pistons and forged h beam rods... Motor has cast steel crank. Compression is at 10.5:1 and edelbrock performer heads and torker2 intake. Any one know limits of a 455 cast steel crank? I want to spray as much as possible with out breaking after the first spray...

[418redz28]

there is no telling. reason why i say that is bc i have a buddy here locally that runs a cast 350 crank and he is spraying 325-350 through a dp and another 100 thru the plate. cant belive the crank has not fell out of the pan yet. however there are limits. a good place to start is around 100hp and slowly work your way up. thats the best as i can tell from what i have been reading and trust me i have been reading alot bc im steping into the world of nitrous myself