All stock 2.08 int and 1.60 ext I think thats right and maybe 10-15 thousands milled off from bottom side so cc's guessing 83-85 cc someone else can chime in here I forgot what the 516's cc were stock,they should raise your comp about 1/2 point right off the bat..milling them would increase it more,prob have some good 2.08 and 1.74's around that would work or best to prob buy new ones but i have some, you would just have to regrind them and bore out the exh seats but hey u work in a mach shop,unless you port them good better off stay with the 2.08/1.74 for more torque on bottom end,you can put 2.14/1.81's but it is close,but if you open up the heads to breath good then hence the bigger valves..and many will have pros and cons about these heads but I have used them many times even with the smallish 1.60 exh...I've always felt these heads[516's] were capable of some decent perf with a little work..
