what solid cam is equivalent to a hyd 268 ?

I have a friend who just Dyno’d a 273 with .030 over 2 barrel pistons, OEM rings, 920 heads, Isky E-4 cam, 340 valve springs, original intake, Edelbrock 650?, made 266 HorsePower up to high 5K. I think, Commando Distributor, but not sure. The point is your cam is pretty big for a street 273. Next 273 I build will have a Racer Brown ST-1. I would not worry about compression, it is what it is, just maximize your tune. You have nice even compression, so the 273 seems sound. One thing that might be holding you back is the distributor. My 64 273 had a 284 duration solid cam and a 600 cfm Holley for a couple years. It ran strong, but not as strong as the E-4 and OEM AFB. I vote for a smaller cam.