I now have a great direct air intake kit available for the 617 81-85 diesel. This kit completely removes the huge oem airbox with the constricted intake elbow into the turbo. With this kit you can really hear the spooling of the turbo and it makes the engine sound more throaty. It really allows the turbo to finally breath. This is the best upgrade to my car that I have have done since veggie. The intake parts to this kit are a 3 inch aluminum chromed intake tube with a 3 to 2.5 high temp rubber reducer with a K&N style air filter that is cleanable. The engine vent gas/oil separator (oil breather) unit is an all metal tig welded high quality design that is indestructable. Take a look below. Basically it allows the engine to vent properly and let oil blowby to drain back to the oil pan.
I'll have a instructional dvd to help you install this which takes about 35 minutes and I am selling this complete kit for $145.00 shipped in the U.S. I encourage you to compare this kit to anything else similar for the price.
Email any questions to jonthecarguy@comcast.net