[Cliff R]

Just take a look at the accl pump Edelbrock uses in them. It's soft plastic pressed into plastic, and the large end will bend nearly 45 degrees it's so loose on the shaft. The light blue pump seal is "soft" and swells up quickly/fails in contact with any concentration of ethanol. I have locals drag those things up here all the time wanting me to rebuild or put kits in them.

I direct them around toward the back of the shop, and tell them that the best sound that carb will ever make is when it "tinks" off the dumpster......FWIW.

The "Thunder Series" copied the AVS design so will have a spring loaded secondary air door in the airhorn. I tested the original Performer Series or AFB clones way back when I wrote the Q-jet book, wanting to test what was currently available dyno, street and track, etc. The AFB clones were HOPELESS on my set-up, and it would puke all over itself with any attempt to bring the secondaries in. The air door just dropped open and it went lean and no way to tune that out.

A few years later I obtained one of their Thunder Series AVS units and did some drag strip testing with it at a private track rental on two different cars we took with us that day. We carried along a couple of Holley carbs and half a dozen Q-jets as well. We were able to tune the AVS for good runs on both cars, but it also ran slower than all other carbs tested that day. It took a couple of hard launches to dial in the spring loaded air door then it really didn't do all that bad, but was down in both ET and MPH on both cars we took that day no matter how I adjusted it or what jets we tried using in it (I took along Edelbrocks expensive tuning kit). Overall I'd still say it was a decent carb, but one day with it certainly doesn't tell us how it will hold up in long term service, or how much fuel it will consume for "normal" driving, etc.......Cliff