Thanks Graham, I did the exact same setup for our 67 273. Does your engine currently have Commando pistons?
Ours had the 2bl pistons and that cam is way too big for the 2bl. Sounds awesome but no bottom end torque at all. Part of our "demise" was stock converter and 323 gears. I'm no engine builder by any means but in my opinion the heads aremt suited for it either. Comps specs even say "smallest cam for 340/360" or something like that.
In my opinion the determining factors are your current pistons.