B44.2 / B44.3 chassis

[Hog]

I've been on the lookout for either an Avid or Schelle chassis for one of my B44.2's, but they're notoriously scarce second hand and expensive new.

Question is - is there any difference between the dimensions and hole placement of a B44.2 chassis and a B44.3? Stock alloy B44.3 chassis is cheaper than one of the aftermarket versions, so if it has everything in the same place it seems the better / cheaper option.

Thanks in advance.
Dave