Simmons Valve

I just moved in and the shower diveter is original and no longer works. The little pop out thing doesn't pop out and I see some weaping water along the sauter.

Anyway, is there much of a difference between valve brands? I see the simmons kit at Lowes but the house had Mowen. Is one harder to install then the other?

And...

Can I (and a helpful friend) use PEX to make the connections? He just got a PEX kit and we wanted to giver' a try.

Thanks.

Your friend needs to be told that PEX and tub spouts is a bad mix.

I would look at fixing what You already have... Call 1-800-BUY-MOEN and talk to them about your valve. They will ID the parts you need and send then to you.