A Moparts member, Larry Curtis, AKA lowflyingDart, built this 572 cu in iron block motor for a local racer.
4.5 bore 4.5 stroke, 14.5 compression, .043 top and 2nd rings. Comp roller with 284/296/112 cam in at 112, with . 836 gross intake lift, .824 ex lift. Intake lobe is a 24140b Comp, forgot the exhaust.Fuel ended up being VP c14+, which produced a few more hp (7?) Than c14. Timing ended at 37 degrees for best power. Carb is a 1250 Dominater, with a one inch high cloverleaf spacer on top of the Indy 3X. If there is a revised 3x, this would be it, new in 2022. Heads are 385cnc 572-13, with a minor touchup at the valve boss area to remove a small lip left by the cnc cutter. The final power pulls with 2 1/4 dyno headers are 962 hp. We tried my 2 1/8 step to 2 1/4 with merge collecters, and gained a few hp, to 967 hp and the increase was from 6000 rpm to 7200. I was very happy to see my headers produce more power than the dyno headers. Mine have a 4 inch collecter with 3 inch merge ( choke) and primarys are 30 inch. Larry was hoping for 950 hp, and considering leaks kept vacuum to a best of 4 inch, it is assumed this motor will make 980 hp when vacuum is up to 10+ inch. All in all, a very good result, IMHO!
I am happy to see this power level, as i have a similar build. Mine will be 550 cu in, but will have narrower . 9mm (.036) rings, ported 3X, methanol, terminater 2500 cfm injection, and the heads are cnc385 572-13 with extra port work by Larry Smith, and a similar duration @.050 cam, but . 032 more intake lift and more duration at . 200 lobe lift. My intake valves have no back cut, so it will be interesting to see how that works