Vaccume on heater and axel question.

[MisterMan]

I have a 71 gmc /w/ ac and i need to know on the back of the ac and heater controll's there is a vaccume hose connector. on it it has a labled face "1 2 3" i need to know what one controlls the heater valve to open.

next question, how much will a flip axel in the rear lower my truck?? (its a leaf read end)

THANKS!!
--DEN

[JimKshortstep4x4]

Can't help you on the axle flip but the vacuum diagrams are attached which show the hose routing. I am attaching the two port and the three port versions.

Jim

[69rut]

Not sure what you mean about "flip axle", but I have some ideas.

If the leaf springs are on top of the axle, then yes, mounting the springs under the axle will lower the truck. How much? My guess is three to four inches.

You do not want to do this by simply fliping the axle over. In order to get the axle facing the correct direction, you will also need to swap ends 180*. This will put the left hand brake assembly on the right side and vise versa. The emergency brake cables will now be pointed toward the rear of the truck, not the cab. Also the brake shoes and other hardware will be backward. This does make a difference in how well the vehicle stops and the performance of the emergency brake.

[68C15]

axle flip drop = diameter of tube plus distance from edge of tube to flat area where leaves rest x2.
like this; assume a 3" tube and 1" height of spring perches. this would account for a 5" drop.

you need to remove the perches from the original location and weld them to the bottom of tube. just make sure you keep the pinion angle correct.

[MisterMan]

awesome!!!!! thaks everyone!!!... ask and i shall recieve!!