Having installed a T5 in my 54 truck behind a 235 I've had to jump through hoops to get it right! Obviously your disc isn't releasing and this can caused by a number of things overlooked.
Hopefully you followed the info in the "search" section about making the necessary mods to the front of your T5 or you wouldn't have even gotten it bolted up.
I found that in prepping the transmission your biggest challenges were in getting a clutch disc that had a FLAT BACKSIDE (I used an RCF-4201 from an 83-84 Firebird/Camaro 2.8L) that went towards the diaphragm pressure plate and extending the splines back 1/4-3/8". But MORE IMPORTANTLY...making sure the clutch disc would actually slide back over the extended splines. If you "assume" it will slide back and don't verify it by actually sliding it back to verify, you will (may) encounter the problems you're having. The throwout bearing will depress the pp fingers but the center will flex and still make contact and remain engaged.
I also found that the remanufacturer mis-label "flywheel side" and that several folks have followed the marking and had the flat side of the clutch disc towards the flywheel. This will guarantee that the disc won't slide back far enough to release. In addition, I had to run my pilot bushing in an additional 1/8".
I'm using the short TO bearing, drive my truck everyday and have about 1000 miles on the T5. I experienced the same problem with no release and discovered that my disc was binding up on my extended splines. Insuring that the flat side was towards the pressure plate and that the disc would slide over the splines did the trick. I've got some pixs and additional info in my webshots "Shoebox" album. I hope this will help you get your T5 set up. BTW...the T5 really makes driving a hoot!!!
Dave
