Cam Question

It’s generally accepted that it is a 2* duration gain. Actual may vary.

The thing with your Edelbrock heads are there rated to be good to .575 lift. What I would do is disassemble the valve springs and see what’s under them. Get a valve height mic and start fishing around on springs to use that will for certain handle that lift.

IF you can not get the spring in with clearance on lift & you have only 1 thin shim under the valve springs (to protect the aluminum from the steel spring eating it up) look to possibly use a valve seat/stem cutter to drop the seat slightly. There isn’t much room to cut under the spring so be careful.

Porting the head would be next in line. IMO, for myself, maybe not you? I’d probably have a pro head porter on it to do both jobs.