Was on a 23 footer thursday night at Moloolaba that had twin 175's on it and 800 litres of fuel tanks in the rear as well and asked this guy if it was boggy in the rear and he said no it wasn't to bad.(Had no pods like yours).
So i spose if you compared the weight difference 2 175's plus 800 kilo of fuel compared to diesel donk and leg might give you an idea Pete? Depends we your tanks are too and what they carry. I dont think you would need them as a spanner boat carries a lot of weight in pots etc. But hey, what do i know.
Darryl.