Fwiw, Chevy used 1.94"/1.50", -461x, small chambered double hump, heads on the 290 and 315hp /283 engines just before the 327 became King.
The 283 I finally got that my Airhead Nephew once owned has a good set of -291, big valve heads on it. It came w/ a TRW TP-146 spec'd at 308/246, 108/106.5, .429" lift hy-cam.
It has flat-top pistons and I figure .039" thick blue composite overhaul kit headgaskets and when I ran the SCR and DCR, it came in about 8.2 SCR and something like 5.6 DCR so really couldn't pull me off my Throne! Sucker sounded good tho.
Notice the 2.02"/1.60" valved double-hump heads and low lift cam to keep the valves at a lower lift to keep from kissing the cylinder wall tops.
The bad deal is that the bigger valved double-hump heads are usually 64 to 66 cc's chamber size so you HAVE to install domed pistons to get the compression up there like GM did back then. They used 1/8" tall, 1/2 round domed cast pistons that can be reversed. I had a cheap $34.95 set from good ol' W/JCW in my old junk301.
You can get away w/ angle milling the double-hump heads BUT this is a real hassle that I care not to get into! Plus, it costs some money to have done!!
The 290hp/283 is 10.5 to 1 CR'd and the 315hp/283FI engine is 11 to 1 CR'd.
A small chambered set of heads so that she is right at 10 to 1, a small 224 to 230 or so duration at .050" lift solid lifter cam, a 600 cfm Holley on a 300-36 and a cheap set of 1.625" dia, 4-tube, long headers and the little-bitty short-stroked jewel will run like a "Scalded-Dog"!!
Add more of everything except headers and gear and tire her right in a small light bodied car like a Vega and go big engine hunting!
PS., and install shim headgaskets!!
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