You're building a near identical motor as I just did.
Isky Cams #201027 Z-27 fits the bill. It's a snotty lil "high perf street" mechanical cam.
282-282 247-247 @.050" .507" gross lift .016" lash 108LSA goes in on a 104 intake C/L try it...
get some 4.10's and some sticky tires.
As long as you did a healthy port job on the heads, you should be happy with the result.
www.iskycams.com