23 CC SeaCraft 1979 Rebuild questions

[armandozx]

Hey guys, first of all I want to thank anyone and everyone who comes across my thread and gives me suggestions. I am in the process of restoring a 1979 SeaCraft 23 CC and my stringers are "busted" or better yet compromised. They are leaking water from underneath; the stringers will be cut, re-foamed, re-glassed and brought back towards the transom.
Next to the stringers I have old foam which will be taken out.

My fiberglass guy said to leave it unfilled because foam absorbs water and that's not what he would like, basically just clean it and leave it unfilled. What do you guys think? Would this decrease the boats buoyancy, would it affect the ride or integrity. Should I re-foam and glass?

Boat has an enclosed transom with bracket and the goal is to mount a single 250hp engine in the back.

Thanks in advanced.