[Chrysler300] 400HP F carbs / AFB maladies

I just noticed in carb listings on our tech site (thank you for that site, and to those behind it---..it gets better and better) that the 400HP F,G H had different AFB carb #s than the regular ram cars (which #’s varied by year) ; The high performance “400HP” cars all had the same carb , however, --across those years. .

Does anyone know what was different on those 400HP carbs ? Larger throttle bores? Jetting?

While on carbs, JY Chouinard discovered the hard way , that the jets had been switched front to back in a 300F car we were working on. Carb does not work at all then, as metering rods are matched to specific jet opening, and placement in primary or secondary positions in carb ; assumptions about which side has the big jets are not always right . I would never have found that personally, you just assume it is right.

Big find by J-Y! Jets and metering rods have to obviously be in right places. (we know that) But no one is looking for that on the jets.

So , something else to be aware of re : balky ram carbs. Jets can be symmetrically mixed up in a rebuild. I also believe the loose venturis held by screws are specific side to side and that the gaskets for those can be put on upside down or switched in position, obstructing some channels . Some channels seem to be blocked off on purpose by those too. Match all parts to metal holes in the carb body and matching venture carefully. Slight differences! That happened to a carb that ‘would not work right” ; I had done it, I did not realize differences in drilling and the little gaskets.. Some carb kits seem to use kind of a universal gasket here, further mixing up the possibilities. It might not be you, it might be someone before you.