The Stovebolt Site Forums The Shop Area The HiPo Shop '49 Chevy 3600 3/4-Ton Brakes

Hi. I'm a new member to the Stovebolt, although I have been checking out the web site for some time. Here's my project...

I am doing a complete frame-off restoration with the intentions of keeping the truck mostly stock with improvements in the driveline to keep up with today's traffic. I replaced the rearend with 4.10 "No Slip" gears out of a '70 Chevy C20. I have a 261 straight six out of a '59 2-ton truck mated up to a "New Process" A833 4-speed overdrive manual transmission out of an early 80's GM truck. The front end has been completely rebuilt with new "huck" style brakes all around.

Since my truck is a 3/4-ton, it seems that brake/suspension options are limited. Here are some questions I have:

1. I would like to convert to power drum brakes, but I have not found a conversion ket for 3/4-ton trucks, even for a dual chamber manual brake master cylinder. Brothers makes a firewall mount kit that should work, but it's a bit pricey. Any recommendations?

2. I would like to get rid of the old "single-action" shock absorbers simply because rebuilt ones are expensive. I like the nostalgia of the original shocks, but not so much if it's going to cost me $500.00. Any thoughts on shock options?

3. Is anyone else running a 261 with an NP-A833? It seems that the Saginaw "2-ring" 4-speed is a popular option, but I like the overdrive idea with the NP-A833.

Any thoughts and/or recommendations will be greatly appreciated.

Thanks!
Dan M.

David, it would help knowing what year truck it is. With the AD trucks (47 2nd to 55 1st) the brake master cylinder and lines on the 3/4 ton are the same as the 1\2 ton.
BTW welcome to the bolt. Send pics.

Thanks. My truck is a 1949 model. One guy told me that the adapter plates available for modern master cylinders will work on 1/2-ton AD trucks only because the offset from the frame is different between the 1/2-ton and 3/4-ton AD trucks.

Any difference can be compensated by a little tweaking.
Here's a shot of mine. http://good-times.webshots.com/photo/2933329710099708909JKYdtC

Here's where I got mine.
http://www.classicperform.com/

Good Morning! Looks good. It looks like you did not need to tweak the original master cylinder bracket, but what did you need to do to the adapter bracket? Also, how do you access the master cylinder cover? It looks like it's set back quite a ways.

Thanks!
Dan M.

On mine I originally filled the master cylinder by removing the transmission cover and using a funnel with a tube. I've since opened up the hole to allow direct access, and made a new cover. Its under the floor mat so no one even notices.

I put a couple of bends in one edge of a rectangular sheet of metal, so it would slip under the floor near the transmission cover, and then simple screwed it down. Works perfect.

The A833 has been used by several guys I'm aware of, and they all seem pretty happy with it. Another option is the T-5 5-speed, but it is not a stout as your A833.

Regarding the shocks I'd look for the brackets used on a later AD truck that had tube shocks and swap using those.

Dan, on the subject of gearing, could you clarify exactly what this means??
“I replaced the rear end with 4.10 "No Slip" gears out of a '70 Chevy C20”
Do you mean that you exchanged the original Eaton HO52 center section for a late model positraction center section and it fits, and are you using the old axles, or the new ones? And have you done this or are you just contemplating doing this? There is a lot of information coming to light recently about carriers other than the Suburban that will fit in the original housings. Finding that other carriers will fit could open up a lot of other opportunities for us medium duty truckers.
Denny Graham
Sandwich, IL

Hi -

Yes, the carrier assembly with 4.10 gears and posi slipped right in using the old axles. The Eaton HO52 and Eaton HO72 used the same carrier. Supposedly the HO72 has a thrust bearing adjustment and was used more on the 1-ton trucks. Other than that, the HO52 and HO72 were identical and were used on '67-72 Chevy 3/4-ton trucks. I have not actually driven it yet, but everything bolted up fine and it rolls good.

Jim Carter has a good tech article on this swap. Let me know if you need anything else. I have photos showing the side-by-side comparison on my swap.

Thanks,
Dan M.

I'd really appreciate seeing your photos Dan. Thanks!
Tim P.

BIG CHEVY 3600,
Which setup did you use on your 3600?

Tim P.

Tim
Check this link.

http://www.classicperform.com/Instructions/PDF/4754BB.pdf