Possibly building a Taz clone-ish.Question on build area

Hi all

I have a scratch built printer I did a few years ago that I based off the Makerfarm design. I have been kicking around reworking it to be more of a Taz style/design. What I can’t seem to figure out tho is what the max build area could actually be.

Currently I have 300x300x300. I know the build area on a real Taz is smaller but from what I have been able to find, the bed itself and the extrusions are the correct size to match everything I already have. I would just need to buy rods and bearings. If I do rebuild mine, is their enough…room?..I guess…on each axes where I could tweak a bit and get the 300 build volume back?