adjusting brakes question

You could put two nuts on against the drum with the brakes released. Don't tighten the nuts too much, just enough to hold.

Set the brakes and the drum should center. Then pull the nuts and install the wheel.

Might lead you in the right direction if it makes a difference.

 

I bet that 6.620 is supposed to or maybe does have a 1 in front of it in reference to the maximum rebore diameter

 

The problem may be the long stroke chambers. All Pete Air rides that I know of have used only standard stroke and the rod is cut only maybe around 3” long. 1-1/2 in stroke is normal if adjuster is set about 3/4 turn loose from tight.

 

We are all over the board here. And I thank everyone.
The 6.620 is 16.620, the maximum worn limit to reuse the brake drum. We need another number.
Sounds like you have hub piloted drums on stud piloted hubs. If you look at the space between the drum center hole and the shoulder or tabs it mates to on the hub they are probably unequal.
I have a small collection of those from trailers transferred in.
In a bind when we had no proper drums we would loosen the lugs. Tight enough to hold the drum but loose enough to be able to pry it around. Eyeball the space between the drum center hole and the hub ( is right by the hub cap ) .Pry the drum around the to make that space as equal as possible and tighten the lugs. Not perfect but that will run until you get the proper drums or a tire guy touches it.

 

As long as they are all the same and the slacks are set up correctly that will work.

 

Did some stuff like that with some White GMC's Steers would vibrate like crazy with brake application. Dealer drums and shoes and still had the same problem. Turned drums and new drums did not matter. Simular deal with the lugs not to tight. Tighten the brakes until they could hardly be turned past the tight spot. Then tighten the brake adjuster as tight as possible and tighten the lugs. That worked pretty good.

 

You should have a gold tag above your clutch pedal. Model number and last 6 of the vin is enough for Pete dealer to tell you what drum belongs on it. ( Unless you have a cutoff or something. )
I do not thank 50 thousands of an inch would be a big deal on a brake drum but I have seen some with sleeves. They fit between the stud and drum. You need at least 3 on each drum.

 

Kind of like the centering devices for hub pilot wheels to get them closer?