Fuel pump convertion on 94 shadow

Start off with I have a 94 Shadow turned CSX. Have 2.2 commin block T2 with a a555 trans.. Front mounted SRT-4 neon intercooler..fifth injector. While running at 18 ilbs of boost..Well I just got done putting on my super 60 computer..52 lph injestors and my 3 bar map..and was now intalling my 255 walbro pump when BAM....plasic sending unit..well I ended up breaking the rusty fuel snout at the top..So I bought another and dissmantled it, then installed the USED (which came off a running car) fuel pump and put it together..turned the key over to purge..and all I got was 20 psi....So I dissmantled it again..put my O.E. pump back in...55 psi..Now my question is...can a walbro pump be put in a plastic sending unit..or do I have to go with the old style ( 90 and older) pump and convertthe pig tail and connected the return line to the float unit? Or do they make a 255 set up for 90-95 turbo engines?

A 2.2 would have a mechanical fuel pump in any case would it not? Not sure what you're doing here.

The 2.2 in my Turismo I used to have, it had a mechanical fuel pump. My dad has a Shadow with a 2.5 in it but it has an electric fuel pump. What do you have, and can you change between mechanical and electric fuel pumps on these engines or what?

bleed dodge, the shadow from 1989 and up only had electrical fuel pumps and fuel sending units in the fuel tank
Well I just got done putting on my super 60 computer..52 lph injestors and my 3 bar map..and was now intalling my 255 walbro pump

that's the clue that this is an electrical fuel pump

he's trying to upgrade to a higher flow fuel pum for the new computer mapping and bigger injectors

other than that, i have no idea why the psi is lower than OEM