BINGO! Just what I had found out as well. At the time, I did t understand the full effect there was. I had collected more than just a few Oder Carter AFB & AVS carbs.
Under the boosters (AVS has the primary only) I noticed different holes in the tubes and different orifice openings and some closed off. This was making me confused. VERY! Shortly there after I discovered that AFB carb thread.
I had tried talking with the Federal Mougal tech line. All I got was a pompous know it asshole that couldn’t answer a single question directly but mostly said;
“It is a sophisticated calibration done by the factory engineers that is well over YOUR head to understand the complexities of finite fuel calibrations & delivery of ….” Yadda yadda yadda yadda yadda….
800 looks to be fine. As a matter fact Joe Sherman stated he used them on engines up to 550HP and they got better mileage than a Holley.
Thanks
I have a 800 AVS. (1st gen, not the improved booster model.) I have a little bit of a reservation on installing it on a 340 that isn’t a power house. I picked it up for a big block street machine targeted for approximately that HP level, as I don’t really have a great need to exceed such levels on this particular build for the street. (It’s on the back burner for now anyway.)