bleunetizen: I ran 4 of them...One for each corner of the cell. On tube directly to the pickup tube off the pump. I put them on standard 3/8ths fuel line so they could move around a bit at different angles. I had my crawler flopped over on its side 90deg, engine still running, and full fuel pressure. I've had the crawler at over 60 deg vertical (up and down) and never a hick-up with fueling. The things simply WORK. Such a silly simple design too.
Installing took all of about 20 minutes once the pump was out of the cell. Of course dropping the Z tank looks like a chore, but once out, adapting the pucks would be cake. I think all you would need is two (one on each side).
I had mine in my cell for years. Nary a problem. After I could trust them on extreme angles, I forgot they were there. Keep in mind I found this solution well after I tried all kinds of measures...Holley pusher pumps, 1/2 gal reservoir, etc. Then 4 pucks and $100 later I never had a problem again (could have got away with two I'm sure).
Nolakrewe: I ran a Hendrix tube chassis, Rover 3.9V8, Atlas, built 60's, King 16" x 2.5 coil-overs, bla, bla, bla...
Took me 3 years to build but it was a blast. Sold it to buy the Nismo! LOL!