With Vortec heads, still 75ftlbs from 520. I had a "good" relatively developed 383, with 10.7:1, bowtie vortec heads ported by a "professional" 230°.600 108° degree cam, with close to 100 dyno pulls on it playing with everything, make 518ftlbs on its best pull(there is a thread on it here) big torque don't fall off tree's..despite what you read. And i'm not saying that my 383 couldn't be improved on either still.B Original wrote: ↑Thu May 17, 2018 5:35 am A moderately docile GM crate 383 is rated at 435 horsepower and 445 lb-ft of torque
But its all hyperbole, we will likely never know the results of the op's engine, It should run decent for what it is.