any thing special i would need to mate teh t4 housing and wheel to my t3 center section??
or would it be the same as changing to the .60 a/r t3. housing, backing plate, and wheel??

 

pretty much the same. For a t3-t4 conversion youll need the backing plate, compressor housing, and compressor wheel... Make sure you get the clamps with the compressor housing, they arent the same as the t3 ones. To go from a t3 42 to a 60 all you should need is the compressor cover and wheel, i think the backing plates are the same, as the .42 and .60 compressor wheels have the same size exducer diameter

 

i the FAQ, it says the T04B S3 housing is the smallest T4. does this come in diff a/r's or is that just one certain size??
would i be looking for a .60 a/r 60trim T4 housing or is that too big

edit:

looking at comp maps a Super 60 is my most efficient option at ~8psi. i would have to run ~11psi to make a t04b s3 worth using and that would be past teh breaking point of d-series rods