Not a hydraboost but I bought 2 vacuum pumps from a junkyard for $20 from an early 80's G-body car. They work great and I have a spare.

http://www.gmcmotorhome.com/tech/vacuum_pump/index.html

 

e bay they have lots !

 

I bought my hydroboost off of a Astro van at Pull-a-Part for $14.00 and customize the bracket to work. The hoses is where the money is. I have about $250.00 in braided hoses and fittings.

 

Buick T-type hydroboost unit off eBay, $200 lineset that was missing 2 fittings, straight booster brackets (chrome) from Summit, modified the pedal pushrod cutting and welding it back together. I think all in all I spent about $350 without new master cylinder, which was $70 for a '69 Corvette dual reservoir one.

Look in my signature, first picture on pg. 5, first 2 pictures on pg. 6 of the Chevelle album.

 

I haven't put mine on yet. Waiting on the brackets from that are about to finish, but I got the hydroboost for $10 at the junkyard and plan on running the C5 master if possible.

 

2000 Safari van booster
Nick's adaptor
about $50 in hard lines

These pics are of test fit, everything is back apart now for paint.
Also have different fitting and hard line for return.

 

got a link to "Nicks adaptor"?
What did you do about the pedal to rod connections?
thanks