No that won't fly.  The T5 has a longer input shaft and the bellhousing is deeper to make up for it.  The toploader input shaft would lack 3/4" of making it to the pilot bearing in the crank, plus the toploader front bolt pattern is wider than a T5 bellhousing will allow.

Now, with enough determination, I supposed you could manufacture a custom pilot bushing and could modify....wait.... Just modify the toploader bellhousing like I did the scattershield mods on my website.  Use a diaphragm pressure plate and a 5.0 release arm and bearing.  Easy...  Here is one a customer did using the web page as a guide.  Allows use of cable clutch linkage with toploader.

Remove original pivot fulcrum
Weld in a boss for the ballstud to screw into
Weld a tab to the side for cable housing stop
Use 5.0 Fox release arm and bearing
Use diaphragm type pressure plate. I have been advised there is a short and a tall version, though I have never seen the tall one.  Use the shorter one, like a Fox Mustang.

http://www.mustangsteve.com/scattershield.html