Bunch of bloody wimps if you ask me..... didn't have or want air back in the day and won't have it in my Sandman now....

If you have a 253 Sandman and are fitting original Holden AC then expect the same performance as a 173 6cyl when the AC is on.... it really drains the power and doesn't work overly well in a van anyway.

As Rodney says, if you really must have AC go modern aftermarket and you'll spend all your time cruisin rather than in the shop getting repaired.