Engine in my '72 Duster is a 340/418" c.i. stroker.

'72 340 Block .040 with a forged Eagle 4" crankshaft
Stock main caps.. ARP hardware throughout engine
Scat 6.123" I beam rods, Keith Black Icon forged pistons- 10.1 comp.
Melling HV oil pump, strainer. Stock pan
Factory J heads, fully ported and polished, stainless 2.02/1.88 valves. Indy Racing 1.5 roller rockers
Camshaft: Bullet Racing solid mechanical, duration .248/.251 @050, gross lift is .530
Edelbrock single plane Victor 340 intake is ported, and gasket matched. Demon 850 cfm carb.
1-5/8" headers, full 3" inch exhaust to the bumper, with I believe Dynomax mufflers.
Never been dyno'd, but some research, with similar combos, I think it could be around 500-510 HP.... a little less/more?
Car runs on pump gas..93 octane