On my 73 450sl there are 2 heater hoses coming out of the rear block. One looks very easy to replace yet the other one dissapears into the fire wall. Where do you access this end. Also do you use just standard heater hose?

__________________
Stable:
1973 450sl
1978 red diamond ice vette
1975 steel blue convertable vette
2002 steel blue dakota quad.