I plan to replace the waterpump on my "new" 740 non-turbo wagon as part of the timing belt/tensioner/seals/hushers replacement project coming up soon.

The upper timing cover of my recently deceased 240 had a shiny replacement water pump and the upper timing cover completely sliced through by the water pump pulley. My 740 timing cover has similar scoring, but has not yet sliced all the way through.
Out of the 6 or 8 timing covers I looked at for 240's and 740's at the junkyard yesterday, every cover was sliced a little or a lot. If the bearing of the original Volvo Pump fails, it can allow the pulley to wobble, which can score the cover which may account for some of the damaged timing covers.

I have searched the archives on this subject and the sliced timing cover is a common problem. One person said the the GMB pump casting was higher than the original where the timing cover sits down over the pump and thus prevented the timing cover from seating all the way. That person shimmed the fan pulley to give clearance to the timing cover rather than remove the pump, grind down the offending high spot and reinstall.

Interestingly, my local independent Volvo repair center has had good luck with GMB pumps that they install with Genuine Volvo Gasket and rubber seals.

It appears that a Genuine Volvo pump is about 2 times the cost of a typical aftermarket pump. On other cars, I have even had pretty good luck with the Duralast pumps from Autozone, which have a lifetime guarantee. Likely to have Chinese bearings, however. I really don't want to use the guarantee.

A genuine Volvo pump runs about $82.
The Hepu pump is about $50, and has been recommended by several of the on-line parts houses.

Can anyone comment on:

Gasket and rubber seal quality of the Hepu pump relative to the Volvo?

The proper clearance (without shims) of the Hepu pump casting -- no interferance with the timing cover seating all the way.

Thanks