Heavy duty rear drums on C10?

[jmil1974]

I know there was an option for HD drums on the rear for our trucks. Was this 3/4 ton + only? Could we do it on a half ton reordering OEM repops? Would they fit on factory axles?

Thanks!
Jason

[Fast68Chevy]

all our rear brakes are 11x2"

you MAY be able to swap off the 2 3/4" rear brakes off a 77=79 Big10 or Heavy Half onto your existing housing and shafts,

the 2 3/4" backing plates are offset different and GM didnt change shaft length to accomodate them

peope typically call the big 10 axles the 5/8 ton axles.
and sometimes trhey go even as far as to say are 3/4 ton or HD, but actually its just the same old 12 bolt same rating, just is wearing wider brake shoes., nothing else differs cept the brakes,

good luck

[junkyardjohn]

JMIL1974 -- I PUT A SET OF DRUMS & BACKING PLATES OFF OF A 75 1/2 TON ON MY 71. I THINK THEY WERE 2.5" OR 2.75". IT WAS A SIMPLE, WORTHWHILE SWAP AS IT GAVE ME ALOT MORE SURFACE FOR STOPPING POWER.

[Fast68Chevy]

2 3/4" = 2.75"
there were only two widths of brakes ever made, 2" and 2 3/4"

good luck!

[junkyardjohn]

YES RANDY .... I LEARNED HOW TO CONVERT DECIMALS TO FRACTIONS ABOUT THIRTY FIVE YEARS AGO. I THINK IT WAS IN THE SIXTH (6.0) GRADE. LOL (NOW IF I COULD JUST GET THIS SPELLING THING DOWN) LOL

I WAS JUST TRYING TO SUPPLY SOME HELPFUL INFORMATION ON A CONVERSION THAT I HAD ACTUALLY DONE, & DRIVEN MANY , MANY MILES, INSTEAD OF "QUOTE" you MAY be able to swap off the 2 3/4" rear brakes off a 77=79 Big10 or Heavy Half onto your existing housing and shafts,

WIDER DRUMS WERE ALSO AVAILABLE FOR 12 BOLT REARENDS ON ALOT MORE YEARS THAN JUST 77, 78, & 79

[MikeB]

Don't know what year your truck is, but I went to 5 lug 71/72 parts on mine when I did a front disc brake conversion back in 1996. The finned rear drums make a big difference in fade resistance. Of course, if that's what you already have, try name-brand wheel cylinders and shoes. I just re-did my rears with Wagner parts and now they are even better. I had been thinking about rear discs, but not any more.

[chevy2racr]

what can I get drums for that aren't finned?

[jmil1974]

Well, I want to keep my 6 lug wheels. Any thoughts on which drums (year, etc.) would fill the bill?

[Fast68Chevy]

Originally posted by junkyardjohn
YES RANDY .... I LEARNED HOW TO CONVERT DECIMALS TO FRACTIONS ABOUT THIRTY FIVE YEARS AGO. I THINK IT WAS IN THE SIXTH (6.0) GRADE. LOL (NOW IF I COULD JUST GET THIS SPELLING THING DOWN) LOL

I WAS JUST TRYING TO SUPPLY SOME HELPFUL INFORMATION ON A CONVERSION THAT I HAD ACTUALLY DONE, & DRIVEN MANY , MANY MILES, INSTEAD OF "QUOTE" you MAY be able to swap off the 2 3/4" rear brakes off a 77=79 Big10 or Heavy Half onto your existing housing and shafts,

WIDER DRUMS WERE ALSO AVAILABLE FOR 12 BOLT REARENDS ON ALOT MORE YEARS THAN JUST 77, 78, & 79

actually the big 10 option was only available for about three of four years, thats what the larger brakes came on because the GVW of them were alot higher than a std C10, so.....
youre really sounding like youre replying in hostile fashion, it seems, are you ok ?? have a bad day or something happen ?

the reason why i said MAY be able to swap is because the housing is narrower just a little bit before 70 and the shafts are shorter also,
and after 72 both are a little longer length,
the 73-up shafts same length as 70-72, yet the housings are little narrower in 73-up than in 70-72
the mid 70s Big10 trucks have deeper offset brake backing plates than the std C-10 had and the wider drums and all 71-up have fin drums and i dont know if any 4x4 could have Big10 option or not,
if so then you can find one of the trucks and take those parts off for you 6 lug 2 3/4" rear brakes,
otherwise you are outta luck

if i can locate my 78 Big10 SPID label around here again I can get the GM RPO code for the Big10 package and find out exactly what years it was available, and i believe was only 77-79, the Gov't caught GM doing this GVW trick on the C-10 models and stopped them from doing it anymore past 79. they didnt have to put ewmissions and cats on the C10 trucks by having the Big10 package on them, 8 leaves per pack and the 2 3/4" brakes allowed GVW of 6200lbs on a C10 which is quite a bit more than a std C10.


good luck

[jmil1974]

Thanks Fast68chevy! Any idea of where I can find out if any 4x4s came with the big10 option? Maybe 4x4s got the HD brakes by default?