Back in 2000, while in the middle of my 3RZ swap, I happened to have both a W56 bellhousing and trans sitting next to a W59 bellhousing and trans. I took both bellhousings off and noticed that the pattern to the trans was the same. I immediatley called Marlin up to ask him if he thought the W59 trans was the same imput and such, and if he thought that I could use it instead of the W59. He told me to hold on and called me back about one half hour later. His response was yes, and ever since then we have all been using the W56.
Original Taco is from 95.5 to 04. and yes the W56 will bolt up to the Taco Bellhousings.
From 05 and current you have a motor called a 2TE and it is also a 2.7 but its not a 3RZ. As for it bolting up to an R sereis trans, I dont recall, but it is possible.
It WILL work... w/ machining. The input on the older R151 and R150(88-95) is too short. Hence the reason you have to specify w/ marlin on what year R150 you're going to use HIS bellhousing on. The R150 from 95.5-04 has a tad longer input.