T2/T3 hybrid?
 

is it possible to put a t25 exhaust housing on a T3? will it work? any other input would be great.

Everything is possible...
I know the garrett gt30r has turbine housings for t2 and t3...
What are your goals?? Why do you want to mix these??

the manifold i have is for a t25. the t25 i have is a pile. i can get a nice t3 easily. what do you think?

it's called a hybrid t28...

it's pretty much a t25 footprint with a t3 compressor wheel. gotta machine the backing plate and compressor housing to fit.

...but you're going to find a hard time putting t3 parts on anything t25, as nothing bolts together...so the only thing you could do is pull the compressor wheel...

the other option would be modifing the manifold to accept a t3.

A t28 is a marriage between a T25 turbine housing and a T3 compressor housing. 25+3 = 28....You are basically wanting to create a T28 but using a T3 compressor side...well like Braineack said it wont fit. Modify your manifold to fit a T3 housing.

or use an adapter plate...

I had this thought the other day too, I was wondering what it took to make my t25 in a t28.

read sr20 forums, they do it all day long.

gotta shift through a lot of shit though....