I've done quite a few R134 conversions on our various vehicles including some MB's, mostly with the York, and am about to tackle replacing the R4 on my '82 300D Turbo. I've NEVER spent more than $300 total for any conversion. Sanden compressors can be found for $100, all new hoses can be made up locally for $40 - $70 and the rest is for brackets, expansion valve, drier and an R134 charge (I have someone do it). The biggest hassle with the whole process is getting the adapter bracket lined up properly so you don't eat or throw belts while running the new compressor.
Now for this upcoming conversion from the R4 I haven't found any brackets so will fab up my own, so if it's not too terribly a PITA then if y'all are interested I could make up more if sufficiently coerced.
I'll be sure to post up pics since I've yet to share much of my handiwork on these forums.
R134 conversions are painfully simple and with a little time spent shopping are inexpensive. I've found them to be more than adequate for cooling W123's here in central Florida, and in my Merkur XR4Ti's it was so cold (below 40 degrees at the vent!) I couldn't ever find a happy medium on the thermostat.
Research and reap!
