heater changes?

[dalepack234]

howdy again yall, i thank anyone who chimed in on my last/first post i have been real busy as i came abon a 85 sierra donor truck!
ran into a small issue thou i pulled litterly everything from cab all wreing from nose to tail with complete heater system, today went to install the heater and the bolts as well as hose fittings asre diffrent from mine, is this normal for parts from a 85 going into a 79?

thank yall again and hope ya are all well

[dalepack234]

nvm yall! i figgerd out its a a/c unit i pulled (wouldnt know the diffrence as the heater hasnt worked on any of my trucks and nvr botherd changing or swaping them) sooo next ? is it a matter of just drilling new holes or? i have all the parts the stuf pluged into (the little round canisters like one was in cab one in the vent door in cab one under the cowl and such)? or is there other issues im going to rub into?

thanks again

[Jason S]

You might clarify a bit...

Are you trying to install a factory a/c system into a heater only cab?
- If so, then the firewall will need some work too - a hole for the A/C plenum will need to be cut and the hole for the heater plenum covered.

Take a look at this link - It will show the relation of the firewall holes for a heater and factory a/c... 
http://forum.73-87chevytrucks.com/smforum/index.php?topic=21690.msg179454#msg179454