I always wondered about their ratings too. I bought the M6270 and when I took it out of the box I found it has only 1/4" pipe in and out. Plus there was a big burr right at the input that blocked about 1/3 of the inlet. I de-burred it so there was no restriction. Also drilled out the i.d. of the fittings as big as I felt I could and them be strong enough not to break. Does it flow 120 gph. I doubt it. But it does what I need it to do. Doesn't go lean on the top end.
I see Holley and Edelbrock both have pumps that look alot like the Carter but are rated at 110 gph. The Eddy has 3/8 pipe fittings so at least there isn't as much restriction there.
