Edelbrock Magnum Heads

Im in the process of building a mild 360 magnum. Im using Edelbrock Magnum heads, Comp 1.6 pro magnum rockers and a cam Comp cut for me. Yesterday I got heads on and got all setup to check valvetrain geometry on #1. I started with a pushrod length of 6.950 since its what Edelbrock trys to sell you so I thought it would be a good starting point...... A No. The rockers are scrubbing from one side to the other and im only getting .540 lift at the valve. Lobe lift is .361 which I verified while degreeing cam so im looking for around .577 at the valve. So longer the pushrod goes... Well pushrod is now at 7.450 and lift is up to .580 at the valve. There's only two or three threads of stud still showing so the 3/8 setup is getting ditched for some 7/16 studs and rockers.