by Malcolm » Mon Jul 11, 2005 8:11 pm
I don't know much about E55F5's, but from what I've seen in comparisons between E51 (mr2 4agze box), E153 (mr2 3sgte box) and E150F(gt4 3sgte box), you should, theoretically, be able to put a 4a bellhousing from your current gearbox or an E51 onto a gt4 E150F (or other gt4 box), which will should work fine on the 4agze.
However, there shouldn't be a huge difference in strength between what you have and a gt4 box, as they're both from the same family, and hould have very similar internals. There may be differences in the transfer box, or the diffs inside the boxes. The driveshafts should fit too, as they do between E51, E153 and E150F.
The rear diff might be able to swap, but if it can then there is also a chance that it's not much of an upgrade, unless you don't currently have an LSD, most gt4's have TorSen diffs.