'61 K10 396ci
 

Hey Guys!

I posted in the 60-66 forum and it was recommended I post here for more expertise in regards to gearing etc. I've recently inherited a '61 K10 in rough shape. It does have a 396 in it though and the price was right at least. She's ugly but if I can get her mechanically sound it could be a cool old truck.

I'd like some help determining what I have in the drivetrain. I assume this is the stock setup but I don't know the history of this truck. Can somebody enlighten me as to what the stock gearing is and the final crawl ratio? I eventually would like to upgrade to disc brakes at least in the front if not all around. Knowing the gearing would help with my upgrade options.

I'm having issues adding images in the post so I attached them, I think...

Re: '61 K10 396ci
 

KOOL truck I'm not sure what your stock gearing would be but I bet it would be low gears, that truck originally had a inline 6 or a 283 maybe even a v6, Wow I just named all the possibilities, being 4x4 and not made for speed back then, course that's assuming that it's still stock running gear...if it hasn't been messed with you might find a small metal tag that's bolted to the front cover...that will list the # of teeth on ring and pinion...
example 41:11 divide that into each other and you got 3:73's..I don't know if I helped you or confused you....I'm sure others will chime in and gladly help...Oh and I really like that winch bumper....

Re: '61 K10 396ci
 

So far everything but the motor looks original. Prolly being a 3/4 it has 4.56s in it, but it's anybody's guess. There should a tag on the front diff, roughly 7 o:clock bolt. Just saw it's 1/2 ton, 4.10s maybe??

Re: '61 K10 396ci
 

Sorry for my ignorance but are those D44's? 4.56 would be great as there are lots and lots of Isuzu 12 bolt rear ends in the pick-n-pull which happen to have 4.56 and they have disk brakes, LSD (some of them. G80) and six bolt hubs.
Also is the TC an NP205 and what is it's ratio?

Re: '61 K10 396ci
 

NICE find! Looks like you have the original Eaton rear (52?), Rockwell T221 (holds up well if taken care of and a closed knuckle 44 in front.

I want the motor mount crossmember that you have in there! Mine has never had one. Its bugged me since I got it!

I got mine from a guy in Oregon who had a 396 in it also. Ran that engine for a long time with no issues.

Cool find. Need more pics!

Re: '61 K10 396ci
 

Just noticed the hood bird, spot light, chicken lights, rear slider and west coast mirrors. Flippin' cool!

Re: '61 K10 396ci
 

Looks to be a Rockwell t221 with a closed knuckle dana 44 front and the Half ton Eaton baby axle for the rear. 373s would make that truck driver decent but unlikely what it has. Pop the cover and read the numbers.

Re: '61 K10 396ci
 

I think 1/2 tons had 3.90 gears but pulling a cover would be best, probably needs service anyway.

Re: '61 K10 396ci
 

^^^^ These +1

Re: '61 K10 396ci
 

I had a 1960 K10

This one is DEFINITELY a K10 half ton (6 lugs on front and rear)

The front axle is a Dana 44
The transfer case is a divorced Rockwell T221 (three driveshafts)
The rear axle is an Eaton (I think HO52) rear axle.

My truck had a 4.09 rear axle with 4.10 front axle (I thought that was odd)

Looking at the front hubs, they are not original. These have (6) allen head screws holding in the locking hub mechanism. The originals had a snap ring retainer holding them in with what I call a "paddle" style locking mechanism. (Just a straight piece of aluminum that is out further than the rest of the hub....not recessed like this one)

The original Dana 44 on these were the closed knuckle type with drum brakes.

The engine is NOT stock (Mine had a 235 6 cylinder with 4-speed manual).

With that rear axle setup and a 396, the axle wrap-up on the rear axle would be a problem. The stock 6' tall shock supports/spacer created a HUGE lever-arm that when in a lower gear, would cause bad axle wrap-up when accelerating, especially with larger tires (33"+). I had to build ladder bars to keep my rear axle in place.

The best way to do disk brakes on this truck is to replace the entire front axle with a newer front axle. I installed a Dana 44 front axle from a 1975 3/4T and swapped the hubs to a 1/2 ton to maintain the 6 lugs.

I also swapped the rear axle to a 12 bolt corporate from a 1979 Chevy K10. I had to modify the spring pads on the rear by enlarging the spring pad center hole and welding an extra pad to the inside, and the springs are narrower on the 60 than the 79.

The Rockwell T221 is a fairly bulletproof transfer case, but leaks like a sieve. I could NEVER get it to seal properly. Repair parts/replacement parts are expensive now and hard to find.

I also added a sway bar to the front from the 75 3/4 T. This very definitely improved the driveability of it. I also added power steering and power brakes from the 75 3/4T. The power brakes was easy since the MC matched the new axles. The steering gear was a bit more. I cut a piece of the frame from the 75 3/4T and made an adapter plate to BOLT it to the frame of the 1960. I also used the drag link that came with the axle and gear.

I also used a 1969/68 body on my frame rather than the original 60 body because there was nothing but a rolling frame with engine, transmission, transfer case, and driveshafts wired to the frame when I got it. No wiring, brake lines, fuel lines, cooling system, or shocks.

Good Luck!

Re: '61 K10 396ci
 

My 61 had 3.90 rear (ho32) and 3.92 in the front dana. One thing i have never seen lock-out hubs like you have on a k10. Eng cross member is from a later year. Not ugly to me lol!

Re: '61 K10 396ci
 

As you have my memory jogging.........Mine may have also had the 3.90 and 3.92 axle ratios to begin with. I changed them to 4.09/4.10......

My hubs were definitely the external type. I can't post a pic here for some reason......
http://www.chevytalk.org/fusionbb/sh...?post/2533540/

The top version shown.

Re: '61 K10 396ci
 

Thanks guys so much for the welcome and the information.

Don't get me wrong, I think it's a really cool truck but pretty she ain't. LOL!

This is my second project vehicle and will take a bit of time to sort out but I'm not on a time schedule.

My first project was my '99 Isuzu VX, here are the before and after pics:

Re: '61 K10 396ci
 

Thanks for the info BILT4ME the axle torque issue you mentioned definitely concerns me. Oh well, one this at a time or I'll never get anything done.

Re: '61 K10 396ci
 

Here are a couple of shots of the engine. At least it has been upgraded to electronic ignition.

Re: '61 K10 396ci
 

Are these broken brackets where the front shocks are supposed to attach?

Re: '61 K10 396ci
 

Yes, I'm pretty sure that's the case on the shock mounts. I have no pics.

On the "ladder bars" for the rear axle: I used 2" x 3/16 wall square tube and welded large fine thread nuts on each end and installed Heim joints on each end. I also welded a pair of hoops to the rear axle tube with a hole near the bottom to direct the torque straight forward into the square tube. I made the square tubes long enough to be the same as thee driveshaft for the most flexibility. In retrospect, I would make them shorter and at more of an angle in order to "plant" the rear wheels better. It tended to wheel hop after that, but at least the tires stopped chewing on the fenders. (I had a 375HP 350 in mine with a 4 speed and 33" tires. It was kind of a poor-man's 4 link rear suspension.

Re: '61 K10 396ci
 

I'd concentrate on getting everything sealed and holding oil if possible. Try and remember that it's a 55 year old truck and should be driven accordingly. I kept the stock rear springs / blocks for 5-6 years of normal truck use behind a 396. Hauling, towing and the like. Never had any real problems. Axle wrap? Yes. Never an issue though. Ran it that way for years until I had the money for the drivetrain upgrades. Springs, t case, trans, rear axle. No more blocks or axle wrap. Ladder bars are the last thing I'd run on a street driven truck. I've had them and they were alot of work to keep adjusted, welded up and working right. IMO they're a band-aid for having weak springs or blocks that are too tall.

For the broken shock mounts - if you can't find any used off of another frame, I'd bet they are fairly easy to fab up out of some 3/8" plate and bolt on.

Get some seals in it, a tune up, make her safe to drive and enjoy. Very nice looking rig!