G, W and R Series will bolt up. I thnk you'd have to modify the crossmember for the W or R, though.
Like he said. G series came on carburated motors, they will bolt up. W series is the 4cyl fuel injected trannys, they are good. R series are the V6 and 4cyl Tubro trannys, they are supposed to be the best. R151F is noted as being the strongest.
Remeber your g52 has the transfer shifter built into the trans., Im on my frist yota but I think the W and R trannys have shifter on the case itself.