Carb for a 340?

Ok I guess ive narrowed it down to the Holley Avenger 670, I have a Holley 600 vac secondary in the shed that id have to send out to be rebuilt but its a possibility, and I have the option to get a already made carb from ProMax

The same carb that we did for the Moparts member would work well for you (PRO 650 Vac). This is based off of a Holley and is a 650cfm carb with vacuum secondary. The carb also comes with an electric choke and our billet jet plate for the secondaries. The customer did upgrade to a quick change spring kit. The carb runs $275 and the quick change upgrade adds $15. It takes us normally 7-14 business days to build a carb. Let me know if you need anything further

i had accidentally posted this under "engines" part of the forum so forgive what appears to be a double post i thought I was in this forum part and could not find this post(since i was in Engines instead of here where the opst actually was).