Where to Buy - Heater-A/C parts for '87 Sierra

[nuckollsr]

I'm anticipating a dash cover replacement on my '87 GMC 1500. While I've got it all opened up, it seems prudent to refurbish hoses, pneumatic actuators, etc on the heater-A/C mixer box.

The pneumatic actuators I've found on the 'net tend to run 45+ dollars each. I'm wondering if any forum members have identified more economical sources for replacement parts? I would just as soon replace them all as opposed to digging back into the job later for yet one more failure.

Thanks!