I'm also in the 500AVS or 600 VS camp.

I never really liked the 450 single pumpers.

Myself...... I'd probably try and hunt down a couple of clean used slightly older 1850 Holleys, since I don't really care for the new version with the non-adjustable floats.
I just can't imagine spending $300+ each for a pair of those.

I'd probably step up to the QFT 1857 instead, but then you're at over $750 for the pair.
About the same $$$ as a pair of new AVS's.


Obviously if you already have the 450's..... I'd try it and see how they work.