If your hoses don't have pin holes in them (like mine had) you should be able to use them with any of the new replacement refrigerants. There is a lot of differences in opions on this subject. Some of the pros say you need to change the hoses, not because of higher pressures but because the molocules of R-134 being smaller they can pass through the old hoses. I have heard many say they have converted over with no problems though.
There is an A/C tech board where you can go and get answers at;
www.aircondition.com/
I looked for hoses fo my 69 for about three years, even bought a couple of sets
at swap meets only to find out later they were the wrong ones. One of the guys in the IRC #chevelle chat room sent me a pair. I took them to a Carquest auto parts
and had the hoses replaced.
They used the old original metal ends and crimped on new hoses for 75.00.
The new hoses are good for the newer R-134 refrigerant if I ever want to change it
over but I put the R-12 back in it anyway. The air-conditioning has been working great
for two summers now.
------------------
Dean Call
Team Gold member #3
A.C.E.S. # 00235
N.C.O.A. # 4350
M.A.C.C. # 001
macc.chevelles.net
[This message has been edited by Dean (edited 11-23-99).]