Question...new pump and tank

[REGALTURBO]

Replacing my fuel tank. Since the original units are no longer available I had no choice but to go with an aftermarket. I noticed that it doesn`t have the plastic baffle inside as the original did. There is one there but it is a metal baffle and slighly lower. Will there be a differance in performance of any sort?
Also, replacing my walbro340 with another. I noticed that the pump housing of my new walbro340 has a foamy/rubbery black material around it. I remember that the first one I put in had the same thing but when I pulled it out it appears as though it disinegrated. Should I keep the rubbery material on the pump housing or remove it before I drop it in?

 

[Turbo1dr]

Will there be a differance in performance of any sort??

I've never had a tank in my Malibu with a baffle. Never had a problem with it however, I'd recommend having more than a quarter of a tank in the car when dragracing. Also, if you like to run on empty all the time...turning corners can starve the pump since the fuel will slosh away from the center of the tank and uncover the pump.

Should I keep the rubbery material on the pump housing or remove it before I drop it in?

All that rubber condom does is help keep the whine of the pump more silent.