1974 620 Brake Backing Plate Rear LHS - Interchanges with?

[Cardinal Grammeter]

I need one and am trying to determine what other models I can use.  

 

A 521 guy thought 521's can be used.

 

I checked a number of the various parts and they are the same (I can't figure out what they call the drum of all things - there doesn't appear to be a pick of the drum in the parts diagram unless it is the impossible to understand parts shown in the pic of the entire truck.)

 

In the 620 itself, I believe the RHS is the same part number but the LHS has 3 different ones - very confusing.

 

There may be the possibility of the early 720 also.

 

Also trying to find a Wagner drum to match the new one I put on the other side.

[datzenmike]

Some drums have a slot that a thin sheet metal lip on the backing plate fits into to keep water and dirt out of.

 

521 drums are all the same.

 

620

Drums are the same through '77 and there is an optional 'anti rattle' drum, but what that is is unknown to me. '78 are disc front and something changed on the rears as they have a radically different number.... they may still fit. Disc brake trucks were ever so slightly wider and the rims much different to clear the front calipers.

 

720

Through '81 are the same as the disc brake 620s, then different numbers.

 

That said they may all interchange as they are all 10" and 6 lug.

[Crashtd420]

1 hour ago, Cardinal Grammeter said:

I need one and am trying to determine what other models I can use.  

 

A 521 guy thought 521's can be used.

 

I checked a number of the various parts and they are the same (I can't figure out what they call the drum of all things - there doesn't appear to be a pick of the drum in the parts diagram unless it is the impossible to understand parts shown in the pic of the entire truck.)

 

In the 620 itself, I believe the RHS is the same part number but the LHS has 3 different ones - very confusing.

 

There may be the possibility of the early 720 also.

 

Also trying to find a Wagner drum to match the new one I put on the other side.

I saw your ad in the classifieds, by the description I thought you wanted the disc brake splash shield...

Are you looking for the drum backing plate?

 

I have a pair of rear drum backing plates from my 72 521.... I just converted to disc in the rear and I have another axle with all the drum parts if I actually needed them

 

If they will work for your application let me know....