I'm working on a Hydraulic setup for my 54. I'm swapping out the complete driveline and the trans I'm using requires a Hydraulic clutch.
Not for sure if you are keeping the underfloor pedals, but I've purchased a Jeep TJ clutch and pedal setup, which seem to be just what the doctor ordered. When scrolling through Rock Auto, a Toyota style clutch master cylinder is what I'm going to use.
I'm not for sure what you'll need for your bellhousing/clutch fork setup. There are a number of companies that make retrofit kits, but they seem to be a little pricey.
I'm thinking you could find something at the parts store that'll more than fit your needs.
The 92 and newer S10's along with the 92-95 trucks have a hydraulic slave that my fit the bill.
The 96 and newer GM trucks use an internal style slave cylinder, which is what the NV3500, T56, and Aisin transmissions use. It may be possible to retrofit to an early transmission.
Here's some links that you may find interesting.
http://67-72chevytrucks.com/vboard/showthread.php?t=577322http://www.hotrodhydraulics.com/GM-Product.htm
