Jer12377

I posted a while ago that my Dana 70 ended its life and it was suggested that I replace it with an 80. All my ducks are finally in a row and I am ready to get one, but I am undecided weather to go with the disc or drum brakes. I measured my fathers 02 3500 with discs and it all measures the same. I have a spare set of rims and the only thing I haven't done is see if the rims off my 93 will bolt to the 02 with out much modification. I figure I will have to change the master cylinder and at that time I will change to hydro boost. MrExtream posted a how to a short while ago on that.
Now my confusion is what is the benefit of the disc set up over the drum? Is it worth the EXTREAM amount of dollars and time to do the conversion to disc? The truck is not my daily driver, all I do is tow a 24' Econoline trailer and haul long distance (600+mi round trips). The truck is 275mi away from me at a friends garage and I have a lot of other mods I am going to do at the same time so time is limited. The mods I am also doing that I have, Power Stroke IC, HE351CW, 4" exhaust, rebuilt Getrag, and If I can find the money , South bend, DDP 80 sticks, new springs (2" skyjacker kit I am thinking?) Oh and it is a dually. Thanks in advance for your sugestions and comments.

Riflemanusmc

Why not upgrade your drum brakes AND add an exhaust brake to take the strain off? Just a random thought....

Jer12377

When I install the HE351 I am going to try to use to stock cast elbow off the turbo so I can up grade to an exhaust brake later. I am waiting for the down pipe from an 05 that I bought from one of the 3rd gen guys to mock up an exhaust system. Its just the money for the rear $?, $900 for the clutch, $750 injectors, $1200+or- for the springs, then the $900 or so for the exhaust brake. I am trying to stick to this order of improvements, the rear is just what is in the works right now.

Riflemanusmc

Just my .02 Upgrade your drum rears and leave them. Shoes and brake clyds. Exhaust brake will save alot of wear and tear on all of your brake system. If you do allitle reading, from what IIRC the 80 has the same axle's and tubes as the 70. If thats so, better off dealing with what you have. Hope this helps.

Jer12377

Yea, now you got me thinking in a different direction. The 70s tubes are 3" and the 80s are 4". I think its is going to be almost the same money to rebuild and mod the 70 or buy an 80. So what I am now thinking is get the 80 with drums and use the dollars for an exhaust brake instead of the hydro boost mod. My 70s pinion gear has 2 teeth riped off with a 3/4" round chunk blasted off of it. The 120 miles I made it after it went didn't help the inside of pumpkin also. Do those exhaust brakes really make that much of a difference?

Riflemanusmc

With a good EB, they do. Saves ALOT on having to use your brakes...DTW is that a GE U2BA in your avatar or one of Dillion's AREO's....

Jer12377

Do they affect EGTs? The more think about it I like the drum with EB idea.
I think its the GE. I know its not the M134, Dillions has a large almost suppressor on the muzzle. Dillions look built better also. I would LOVE to play with one!

archer39

What about using a 14 bolt out of a chevy. When i was thinking about converting to disk i would have been better off find a 14 bolt with disk brakes. Plus they are just as strong if not stronger than a 80 plus there are tons of parts avaible for them.

GLHS

If you have a 4x4, are 3.54 gears available for 14 bolts?

Jer12377

I 2nd that question. Also do I have to cut and weld for the spring perches, is the with the same, and will my rims work? For me I know the 80 will bolt right up so there would have to be a serious advantage in going with the 14 bolt. Also did Chebby fix there problem with there wheels coming off, I thought that was a problem with the 14 bolt?

archer39

i am only going off what i remember from researching it about 4 months ago. I really can't remember about the 3.54 gears but for some reason i don't think they are. I am sure someone with more knowledge than me will chime in. Or check out pirate 4x4.com. there is a wealth of knowledge on there.

92roughstock

I dont see what all the fuss is over disc brakes. Sure, they grab harder, but you have MUCH less frictional surface than with drums, leading to the chance of overheating. I installed a D80 (needed a new axle, and that's what was available that was cost effective), and with the increased brake area, it made braking MUCH better than the 12x3 of the D70. My vote is for D80 drums.

You will have to get some flat faced wheels to use on a D80, no matter what vintage you get. 1stGen= 5/8" coined fit; 2ndGen= 9/16" flat faced.

Riflemanusmc

Yea, its a U2BA GE, We bring good things to light!! lol

Jer12377

LMAO!!! Dillion has a bunch of vids on there sight that are AWESOME to say the least. All I found was that pic for GE.

The more I think about it I have to agree, if the discs are so good how come big rigs still use drum on the whole truck and trailer. I think I am convinced that I am going with the drum 80 and an exhaust brake like Riflemanusmc suggested. As for the coined part, I think on the 80 the drums are on the out side of the hub so it can be removed for brake repair. I was thinking of just coining the outside of the drums to fit my rims and getting different lug nuts.

SkinnyBTN

Just throwing this out there. When I installed rear disc. brakes I noticed a HUGE difference in braking. I will not go back to drums. Just my $.02.