Go with the 1.6 rockers, just make sure the pushrods clear in the head, dont worry about spending much time on the ports, clean out any casting slag though, but i would clean up/ blend the bowl area, thats where all the low and mid lift flow will come from, your intake and headers will be fine, but i would go with a different converter, the stock will work but a new 3000 converter with your 3.23s will make for a much more fun ride.
Fwiw dad had a bone stock 1965 383, 8.5:1 compression, stock heads, with a mp 528 solid cam, 1 3/4 headers, street dominator intake with an 850 holley that went 12.65 In a 3500lb b body with 4.56 gears, those little 383s are runners!
