BLP is a leader in Holley carb work. See http://blp.com/cart/
I am fairly certain Cobra Automotive is using BLP. I sent my 715 Lemans bowled Holly to BLP for a going over. My carb originally was a Carb Shop Stage 3 from Cobra Automotive. They pulled everything relating to the choke (more CFM, cleaner air flow), cleaned and colored the body, did the shafts, put in their billet metering blocks (colored to match the OEM finish), put it back together and put it on their dyno motor. I bolted it on and have not touched it in two years. Car started immediately. Very crisp response.