340 Heads Recommendations- Aluminum vs Cast J

If they are the 2.02 j heads and are crack free. Just run them.

My current set up is 340 .30 over with 10.2-1, comp XE285HL, roller rockers, stock airgap, 750 DP with 2.02 J heads, right at 390HP per a superflow 901 dyno.