Brake drum size

[canman47]

I'm new to this site so I hope this question hasn't been covered lately. I'm starting to restore my 68 W200 which has been a faithful work truck for 30 years. I'm also scrapping my 70 D200 and want to use some of the parts including the almost new brake drums. The Chilton manual I have says that drums up to 68 are 12 and1/8 diameter and 69 and later are 12". They seem to look and fit the same. Are they interchangeable? Do I just have to use the later brake shoes or does the 1/8 inch even matter? Is the rest of the hardware the same? I remember when I needed drums on the 68 many years ago they couldn't find them and sold me a 69 instead so I have at least one of those on there. Any info is appreciated.

[fosh69]

You wouldn't think 1/8" makes a big difference, but the bigger shoes would contact the smaller drum on the ends and have to wear into shape. You wouldn't have full contact shoe to drum. The opposite would be true with a bigger drum and smaller shoes but, the contact would be in the middle of the shoe. Which ever drum you go with, make sure you get the matching hardware and, test fit the mating surface before installation.

[powerwagonpaul]

both my '67 FSM and my '69 FSM show the drums as 12 1/8 by 2 no change shown in the 70-71 suplement either so its the same size shoes anyway

[Hobcobble]

both my '67 FSM and my '69 FSM show the drums as 12 1/8 by 2 no change shown in the 70-71 suplement either so its the same size shoes anyway

Does each FSM & the supplement list them under the same part number?
John

[powerwagonpaul]

the specs are the same but no part number is shown. that is a different book. who was it that had the parts book? was that LC in PA?

[Hobcobble]

the specs are the same but no part number is shown. that is a different book. who was it that had the parts book? was that LC in PA?

Whoops.... I should have read more closely.... I can help with an earlier year [pre-'69] part
number if LC doesn't have the older parts manual.
John

[canman47]

My usual parts suppliers have listings back to 69 but not before so I'd like to be sure they're the same drums before installing. Kragen has listings for either cast iron or steel. What's that about?

[powerwagonpaul]

im kinda wondering about part numbers myself, wondering if i can use these drums from the '65 on the '69

[canman47]

Today went to Brake Parts Supply which deals in nothing but brakes. They also have no listings for drums prior to 69 but they could confirm that 69-71 is 12 1/8 x 2" which is the same as my 68. Looks like my Chilton book is wrong. Still don't know why nobody lists prior to 69 if they're the same.