I've been cleaning parts and I rubbed off the marks I had put on the spindles.
I'm prepping for a 9 to 10" drum sbp swap.
Is the pattern of the four mounting holes on the 9" drum back plate the same as the pattern on the 10" ?

How can I identify which back plate or which spindle are Right and Left??

I believe they are identical, dude.....

D/W

_________________

If it ain't broke, fix it!

What do you mean?
Are the 9" and 10" spindles identical?
Is it just the hole pattern that's identical, or is a 10" right spindle interchangeable with a 9" right spindle?

If memory serves correctly (a big if! ), all of what you just said.

D/W

_________________

If it ain't broke, fix it!

I could be wrong, but I recall that left and right suspension parts on Mopars are labeled by part number with even numbered parts belonging on the right side and odd numbered parts on the left (driver) side.

What doesn't help is that the part numbers cast into the spindles/knuckles are very difficult to see...or even "not there" at all. I have some 10 spindles sitting in a box in this room, and I tried to read the P/Ns on them, but because of paint and wear over the years, they are nearly invisible. I can't tell you which side is which without looking at them on a car, sorry.

I don't think 9" drum backing plates will bolt to the 10" spindles. Also, the left and right knuckles are definitely different.

_________________
'68 Dodge Dart 4dr Sedan

thanks.
One of them has a number that ends in 986.

One of the holes in the spindle is threaded.
It needs a special bolt.
It's a 1/2-20 x 2 3/4" grade 8 bolt with threads to within 1/2" of the head.

It's unavailable.

Do you use an old used bolt or drill out the threads and use a new bolt?

One bolt broke and I lost the other. I am hoping there are two in my 9" spindles...

When I took the 9" brake assemblies off my car I noticed the hole pattern looks like a perfect rectangle on the 9" backing plate and spindle,
but the 10" pattern is lopsided, with one lower hole higher than the other.
The lower balljoints don't look close enough to help.

I need to see a 10" brake with the drum removed, but far enough back to see which side it is.

OK. I think I see.
If I put the correct spindle with the correct lower balljoint, the balljoint shaft points towards the upper balljoint hole.