There have been issues with some 2wd pumps also.
I use a std(2wd) pump, there is no need for all this HP on 99% of yb's, even the 8500rpm race engines that are warranted by the place where I get my pump are std pressure.
All of the pumps are stripped own and measured every which way they can be, resulting in up to 50% reject rate, but also every pump they supply is also up to the job that way.
The owner/supplier built his first engine at age 14, 54 years ago, which went on to win it's class.
tabetha