355 CI 230 @ .050 .550 lift 1.6 intake 1.5 exhaust Flat Tappet 10.8 Compression Performer RPM air gap out of the box 20 year old 3310 AFR Eliminator 195 direct out of the box 1 3/4 standard out of the box headers No exhaust Water Pump only SAE Corrected HP 480 SAE Corrected Torque 450 All done at 6500 Idles at 650 Amazing amount of power for OUR dyno which I know is "correctly" "corrected" to OEM spec. SAE correction factors. Given EVERY other combination of 355 that has been on this dyno over the past 10 years or so I would have laid a $100 bill on the table it would have spit out 420 to MAYBE 430. I would have been 99% certain...before the trigger was pulled that is. Got to say, based on my eyeballs why would you even THINK about another cylinder head. I hate to say it but christ, what a sweet running engine that makes a PILE of power with so simple a short block. This engine is also getting the new FAST Easy EFI conversion. Had that installed this afternoon but ran out of time to run it for much more than 10 minutes. This system does fuel only, no spark control, and AUTOMATICALLY adjusts the fueling to meet your target A/F ratios, unlike some of the other easy to bolt on EFI systems. Have to say, in the few minutes we had the engine running it works as well as the AFR heads perform, fantastic. The auto tune is extremely fast. Should have full testing on the EFI done later this coming week.