Doug, your heads are Craft cnc ported heads. I put my valve job on there, but the chambers are standard Edelbrock style chambers. Those heads would require welding to employ my Pro Port combustion chamber. 37° is the right total timing for what you have. I would want 18-20° initial. You want all the timing in by 3000 rpm, but you should check the total timing at 3500 rpm. Most mag trigger style distributors will back up 1-2° by 3500 rpm........it just happens.........so set the total timing at 3500. If it isn't right at idle, a recurve is in order.
