I have a set of used steel lower ball joints to replace the aluminum ones on the '78. The boots show some slight cracking but are not torn through. Can the boots be replaced? If not, what could I use to restore the rubber?

 

From what I've found, the boots are replaceable if you can find them.
You could check with the bug 3 or go to an alignment shop and try to match them with something.
Failing that, some type of rubber restrorer might work for a while.
I've seen rubber restorer for trim and wiper blades, but I'm not sure how they'd do on ball joint boots.

<a href="http://www.nationoil.com/products/car.html" target="_blank">http://www.nationoil.com/products/car.html</a>

 

928 International has them in stock (they are the same as the uppers, too!).
Porsche does NOT sell them separately, but they have sourced them with an AUDI part number.

$15/each.

 

I'm sure the used ball joints will be adequate, but how do you rationalise not dishing out the dosh for new ones?

 

Does anyone have the Audi boot part number? I got the used joints and brackets off a parted out low mileage wreck - as spares for my '87. Thought I might use them on the '78. I may be tight, but I'm not cheap.

 

It is like from an OLD Audi 100.

I was unable to find it locally. 928 SPEC also carries it. I got the P/N from Dave - but cant find where I wrote it down. THey were out of stock, but I got it from 928 INTL