1968 383 stock cam specs

I believe that Darren {original poster} is 'not' pulling the Cylinder Heads.

If that's the case, a 'stock replacement' is the best choice.

The Speed-Pro #CS1098R is a good replacement Camshaft..........Cost $115

Note; It has a little more 'duration' and 'overlap' than a Stock Camshaft, but works
nicely with a Stock 383, and gives you another +12 HP.

Lift............... .420"/.443"
Duration....... 278*/288*
Duration....... 204*/214* @ .050" Lift
Centerline..... 112*

RPM Range... 1200 to 4500