Need help with edelbrock 1406 carb

Welll, Carter sold to Federal Mogul. Federal Mogul kept the fuel pump division and sold the carb division to Edelbrock. They introduced the AFB series Carter carbs as their Performer Series. The AVS2 line is basically the AFB/Performer carbs with some revisions. The main revision is the primary boosters are annular. This gives a couple of benefits;
1: better throttle response off idle.
2: better fuel atomization. This breaks up the fuel droplets smaller, aiding vapourization and fuel economy.
The secondary air valve is controled by an adjustable spring instead of counterweighted. The AVS2 (Air Valve Secondary) does not have secondary boosters.
The annular boosters can be installed into the Performer and probably the Carter AFB carbs. The 1406 is rated at 600 CFM, while the equivalent AVS2 1906 is rated at 650 CFM. If you change out the Performer boosters for the AVS2 annular boosters, Edelbrock recommended the 1906 base calibration to start and tune from there.
I have an Edelbrock Performer RPM Airgap manifold on my Ford 289. Airgap manifolds do not have the heat in the runners regular manifolds do. This is part of their advantage, however the lack of heat restricts vapourization. This is where the annular boosters aid in the fine atomization and vapourization of the fuel. If I was just now performing the manifold and carb swap from the 2V, I would purchase the Airgap and AVS2 carb. At the time I purchased the Performer 1406, there were no annular boosters available, 20 years ago. This is a street rod 40 Ford so gets limited miles per year. When I found out about the better atomization in the Airgap runners with the annular boosters, I started the parts chase. If interested, call The Carburetor Shop in Forest Lake, Minnesota.