eheim 1048 'mod'
 

I'm in the midst of building my new rig. I went with an antec 2650, the smallest full atx mid tower I've seen, so its a tight fit.
These new pci-e vga slots are set really low and are causing tubing routing problems as well. My eheim 1048 is a pretty longish pump, but mostly because of the added inlet nipple....it's very close to my vga block, far to close for a gentle tube bend.

I've found that if I unscrew that nipple, I can fit 3/4" ID hose around the inlet housing. It doesn't have a lipped barb, but a clamp should keep things water tight.
I'm planning on running that 3/4" tube from a small custom res, which the vga block will dump into. This kludge will give me the leeway I need, and perhaps the eheim will benefit from the improved inlet restriction and flow better.
Any ideas as to how much?

The rest of the circuit is a Cascade, an mcw50, and a pa160.

I don't see that pump getting a huge increase in flow. The pumps that see the most benefit are the ones that have higher flow rates. It was kinda like the DDR situation two years back between the Athlon XP and P4C. The P4C was memory bandwidth starved (think RDL-20) so it benefitted from DDR500 (less intake restriction). The Athlon XP wasn't bandwidth starved (think your pump) so it didn't benefit from DDR500.

I will say that running a 3/4" inlet from my custom res to my eheim 1250 greatly helped flow. Now a 1250 isn't a 1048, that's for sure... I have no hard numbers, but I can say that the system bleeds bubble free in about 2 minutes!