67 Dart 270...Project Old School

I have been trying to find a camshaft for the Magnum engine. I contacted Comp for a cam recommendation and they recommended a custom cam with 230/236 .050, 110 LCA, and .577" lift. Based on the flow charts I found on Shady Dell for stock Magnum heads, they pretty much max out at .550" lift.

I have looked at regrinds but the LCA is always 112 - 114 which seems wide for a street/sometimes strip application. The lifts tend to be lower and would most likely work with the srings currently on the heads.

The only off the shelf cam I have found that seems like it might fit and work with a spring upgrade is the smallest Comp Thumper roller cam. 227/241 .050, 107 LCA .545" lift with 1.6 rockers. I am not wild about the excessive exhaust duration.

How much lift do you lose at the valve due to the pushrod geometry? I was thinking .020", but I think it is worse with 1.6 rockers and the much higher lifts.