Mike,
Here is a link to how I added a hydraulic clutch for a T56 in my '65.
http://67-72chevytrucks.com/vboard/s...d.php?t=300087
I moved the T56 shifter location to use stock bench seat.
http://67-72chevytrucks.com/vboard/s...d.php?t=300892
Here is a link to my 6.0 LS2 with T56 install.
http://67-72chevytrucks.com/vboard/s...d.php?t=413880
I run 1800 RPM at 75 mph. The truck is very happy in 6th gear at 50 mph but of course it is not a big block. The overdrive is really nice for highway cruising, should be good with big block too.
I have run this combo for 9 years now. No problems except the shifter rod came loose at the attachment in the cab. Scared me but just required bolt tightening.
TR