tThe fan and motor in that picture is a NAPA motor and fan and their proudctsare always good, But I went with A/C Delco I saw in another picture, I find it easier to order from rockauto sometimes. This a/c delco is for a 96 corvette, were the off set motor and fan makes the fan 1" longer. so thats why the spacer, and its a larger amperage motor (so they say, haven`t seen the spec. difference) So longer fan and motor. I will try anything once, I found more pictures, the spacers
https://cimg1.ibsrv.net/gimg/www.cor...3faa6995aa.jpg
https://cimg8.ibsrv.net/gimg/www.cor...3ed80c6998.jpg
https://cimg2.ibsrv.net/gimg/www.cor...4a792b08ee.jpg
look to be plastic, they look like mock-ups and not for sale.(how easy would that be to just buy a spacer?)

Also found a reference chart on amazon (should be right) They made this fan and motor for a lot of vehicles.

https://cimg3.ibsrv.net/gimg/www.cor...c48c02aea1.jpg

From what I can find 1984 C-4 cars used two fan types, some like C-3`s and a longer one. C-5 used all long types, looks like. Spec`s on the blower motors and fans are not very good. So beware . Found numbers that should be good, two are from these pictures above. NAPA BK #655-1778 used from 86 to 96 corvetts, A/C Delco #88959521 and GM # 12491240. So 86 to 96 corvette fans should work. DIY on the spacers as far as I can find.

Let us know how it works out and if you notice increased air flow. I'm still worried that the extra portion of the fan being partially hidden by the spacer and whether or not that will restrict its contribution to increased air flow or not.

Ok I will check it out, got the fan and motor today. It will be a few days for the 1" plastic. I will let you know, once I get it together.

Don't waste your time fixing what was junk, when the car was new. install electric headlight motors, and be done with it.