Air conditioner

I have a 1976 corvette that I can’t cool down the fan on high wouldn’t be able to blow out a match an inch away.I been to two shops checked it out everthing working been told old vettes had this problems for years.Any ideas how i can increase the fan speed?

Either the blower motor is worn and dragging, there’s a voltage supply problem to the fan which is causing a lower speed, something is wrong with ductwork flaps, the blower motor squirrel cage (plastic) has disentegrated with age and is missing a number of fins, or the evaporator is caked up with decades of dirt and fiber particles.

I think both of those shops have fed you a little BS because they simply don’t want to mess with the car.

Does the blower motor itself sound like it’s running fast on the HIGH speed setting yet little air is coming out of the vents or does the motor sound sluggish?

They checked duct work its ok motor sounds good on low/med/high but I haven’t pulled it to check squirrel cage thanks I’ll try that.