I have a brand new set, still in GM boxes. They were surface milled slightly to bump up the compression. When dry-fit on a 350 block, my Eddy Vortec RPM manifold still lined up if you use silicone on the ends and skip the rubber seals. These should now make a spot-on 10:1 with a typical stock GM shortblock with the 4-eyebrow pistons and a .015 head gasket. I'll part with the heads for $550 and the ride. JEGS is $640 without the milling. Sidenote: With a generic Z/28 spring and the Milodon raised split locks, the Vortec will go beyond .500" lift. My engine is at .550" and I did not mill the guide bosses. Milodon split locks ($25), and I used some generic $25 steel retainers that I dressed the bottoms off a little and I ran .550. If you want even more flow, pop the valves out, dress down the ridge on the back of the factory valve back-cut. A little (3 mins ea port) debur in the port pocket under the seat. A few simple mods and these already excellent heads will scream. I also have some polished aluminum, smooth valve covers still in boxes. I'll include them for $50. Everything in NJ> I have access to Greyhound..cheapest for heavy items. Can ship however you want.