Something does not compute;
In a previous post, the total tub room was computed to be 14.75.
This last post the total tub room adds up to; 11 + 1.75 +.75 = 13.5 inches
Where is the missing 1.25 inch?
I think it is in the section width.
A 295/50-15 should have a 275mm section on a checking rim of 70% of that 275mm. Converting to Imp we get 295 =11.6, on an 8 inch rim. On a 9 it will be a solid 1/2 inch wider so; 11.6 + .5 =12 . So are you sure the rim is 9? and How accurately was the section measured?
In any case, you have 1.75 + .75 = 2.5 inches clearance.Then 325 less 295 is 30 mm or 1.18 inches. If you add .5 for expansion on a 10 inch rim, that totals; 2.5 less (1.18 + .5 ) = .82 for sidewall clearance.
Once again; a 325 is measured on a 70% rim so; 325 is 12.8" section on a 9" rim. Adding .5 for a 10 inch rim we get 13.2 section. This into a 14.75 tub, leaves 14.75 - 13.2 =1.5 extra,meaning the 325 should fit.
And I already know that a 325 on a 10 fit into my STOCK tubs(just); so you should have up to 1.5 more (your mini-tub dimension),clearance than do I. Since I have about 1/2" total clearance, you should have 2.0
Almost all section widths tend to vary somewhat from the math, so here we have three separate witnesses that speak to 325s on 10s fitting. The clearance could be in the neighborhood of .82 to 1.7, perhaps as much as 2 inches.
Ima thinking you might be able to put those on 12 inch rims and have a considerably more stable platform. The 2 inch wider rims might add an inch or slightly less to the section. So now it is getting tight again. Since I know how those babys corner on 10s at 20 to 24 psi (terrible. That's why they are not under my car full-time) , I highly recommend to at least try 12s in 325s.
Unless you are not into hard charging through corners; then the 10s might be ok. But here is the thing;to get 325s flat to the ground for long treadlife, the pressure has to be dropped way down. Under 20. Cornering with fat tires on 20psi, if you have never done it, is a real wake-up experience the first time, and a surprise every time following. Slow down for the first merge;way down.Please!