if its a stock 454 ( or close ) don't run it over 5400 RPM when trimmed out to the max ( indicator + 6 on a 0-10 ) @ WOT .
If it turns that @ 3/4 throttle your prop is to small ( pitch )
If it turns less then 5000 , its to big !
Hope this helps , to at least get a guid line ! :cheers2: