What's the differnece?
Le Mans Master
Joined: Aug 2003
Posts: 7,720
Likes: 12
From: Chattanooga TN
According to Hollander 80-82 is the same and has no interchange. It is their 495. Not sure if that is due to the housing or what. I would have thought that the pump without housing and pulley would have a very broad application.
Le Mans Master
Joined: Aug 2003
Posts: 7,720
Likes: 12
From: Chattanooga TN
No, pulley is different and I think the 81 has metric threads. It might work, but it would be a trial and error process. Try the parts houses, it's probably not that bad. If it is just leaking, get a rebuild kit. Be careful with the vanes, they must stay surgically clean or they won't slide and the pump won't pump.
Le Mans Master
Joined: Jul 2000
Posts: 6,001
Likes: 113
From: Saginaw Michigan
The 1980 pump will swap fairly easily into your car as long as you have a small block. Here are the differences.
The driveshafts are different. You will note that your 1971 pump has a driveshaft that uses a nut and key to retain the pulley. General Motors changed from the nut and key design to an interference fit design in 1975 on all of their power steering pumps. So the 1980 driveshaft is completely smooth on the outside diameter and has some splines inside the end of the shaft. If you look deeper in the end you will also see that it has a 3/8-16 UNC tapped hole down inside the driveshaft as well. (You need a special tool that screws into the tapped hole to remove and install a 1980 interference fit pulley.)
You will need the correct pulley with the interference fit hub for SB Corvettes from 1975 through 1982 for your 1980 pump to fit your 1971 small block. If you have a 1971 big block, I think you are in trouble. Since the driveshafts are different, I know that there is not an equivalent Corvette interference fit big block pulley. Whether or not some BB truck pulley after 1975 will work, I just don't know.
The discharge fitting on the 1980 pump is designed to accept a metric o-ring hose. Just swap the discharge fitting from your 1971 pump into the 1980 pump.
The tapped mounting holes on the front face of the 1980 pump are metric. They are M10x1.5. Your 1971 pump had 3/8-16 UNC tapped holes. You will need the metric bolts to attach your new pump to the the engine bracket(s).
The two mounting studs on the back of the 1980 pump are also metric. However, you should just be able to remove the studs from your 1971 pump and swap them into the 1980.
The reservoirs look different but the 1980 reservoir should fit your 1971 brackets. If I am wrong and there is a fit problem, just swap the reservoirs (you had to remove and replace the discharge fitting and the studs so the reservoir can be swapped at that time.)
So in a nutshell, you will need two or three metric bolts for the front mounting holes. You need the correct interference fit pulley. You can swap the discharge fitting and the two rear studs. Swap reservoirs if you have to.
The driveshafts are different. You will note that your 1971 pump has a driveshaft that uses a nut and key to retain the pulley. General Motors changed from the nut and key design to an interference fit design in 1975 on all of their power steering pumps. So the 1980 driveshaft is completely smooth on the outside diameter and has some splines inside the end of the shaft. If you look deeper in the end you will also see that it has a 3/8-16 UNC tapped hole down inside the driveshaft as well. (You need a special tool that screws into the tapped hole to remove and install a 1980 interference fit pulley.)
You will need the correct pulley with the interference fit hub for SB Corvettes from 1975 through 1982 for your 1980 pump to fit your 1971 small block. If you have a 1971 big block, I think you are in trouble. Since the driveshafts are different, I know that there is not an equivalent Corvette interference fit big block pulley. Whether or not some BB truck pulley after 1975 will work, I just don't know.
The discharge fitting on the 1980 pump is designed to accept a metric o-ring hose. Just swap the discharge fitting from your 1971 pump into the 1980 pump.
The tapped mounting holes on the front face of the 1980 pump are metric. They are M10x1.5. Your 1971 pump had 3/8-16 UNC tapped holes. You will need the metric bolts to attach your new pump to the the engine bracket(s).
The two mounting studs on the back of the 1980 pump are also metric. However, you should just be able to remove the studs from your 1971 pump and swap them into the 1980.
The reservoirs look different but the 1980 reservoir should fit your 1971 brackets. If I am wrong and there is a fit problem, just swap the reservoirs (you had to remove and replace the discharge fitting and the studs so the reservoir can be swapped at that time.)
So in a nutshell, you will need two or three metric bolts for the front mounting holes. You need the correct interference fit pulley. You can swap the discharge fitting and the two rear studs. Swap reservoirs if you have to.
