How to figure out what I have ?

[scikotic67]

I just traded for a 67 3/4 ton long bed gmc with a 327 i believe and a 4 speed on the floor. The truck has manual locking hubs and instructions on the dash from dana on how to lock them, my question is were can i look at to figure out what front and rear axle i have and what transfer case and gears i have. Any place I can see on the motor and trans to give me more info on tranny and motor in my truck and to make sure its original ? thanks

[swamp rat]

Welcome to the forum from Washington, i see your new.

If you pull up the search and search things you'll come up with a ton of threads that will answer your questions.

"NP203 PN205 difference" "what tranny is this" "ID my differential" ect. Just play with different key words, its hard for us to answer without pictures.

[Altec]

Originally Posted by swamp rat

Welcome to the forum from Washington, i see your new.

If you pull up the search and search things you'll come up with a ton of threads that will answer your questions.

"NP203 PN205 difference" "what tranny is this" "ID my differential" ect. Just play with different key words, its hard for us to answer without pictures.

Yep, that pretty much covers it. The only thing that can't be easily checked is the gear ratios.

If you still aren't sure on anything, snap some pictures, and post them!

[scikotic67]

Grab pictures tomorrow,
Posted via Mobile Device

[mikewayne]

your are not very specific.... you should post some video or phtos of you ride... by this post nothing can be figured out... just do this stuff so we can help you!!!

[81ShrtBox]

Look in the glove box 1st... I went thru all this and opened the glove box one day and found the original sales slip had everything right there...

[special-K]

What you should have is a Dana44 front axle with closed knuckles and drum brakes,an HO52 corporate rear (round pumpkin cover),SM420 4spd transmission,and a Rockwell transfer case.Is the knob on there with the pattern?Tell us that and we can tell what it is.alao,where's reverse?Back to the left or right?Do you have lock-out hubs?Are they all steel with a small steel knob that doesn't recess?The original equipment would look like this.

[scikotic67]

[QUOTE=special-K;4356948]What you should have is a Dana44 front axle with closed knuckles and drum brakes,an HO52 corporate rear (round pumpkin cover),SM420 4spd transmission,and a Rockwell transfer case.Is the knob on there with the pattern?Tell us that and we can tell what it is.alao,where's reverse?Back to the left or right?Do you have lock-out hubs?Are they all steel with a small steel knob that doesn't recess?The original equipment would look like this.[/QUOTE

k reverse is to the driver and down next to second not fourth, the hubs are metal and they do not reset, thats bout it ill post pics up right now.

[scikotic67]

some pics

[scikotic67]

sorry for the order

[scikotic67]

and a few more

[67gmcstepside]

Thats not a HO52 in the rear. And from what I have read on this site those blocks in the front are a disaster waiting to happen. The front looks correct for ther 67's.

[Altec]

Front Axle is a Closed-Knuckle Dana-44.

Rear Axle is a Dana-60 (Confirmation?)

Transmission is a SM420 (Judged by shift knob)

Transfercase is a Rockwell T221 (Confirmation?)

[scikotic67]

ya the lift is retarded, and the exhaust is junk , the engine compartment needs help, just trying to figure out more on it before i start ordering parts, were can i figure out that its the right motor for the year ?

[scikotic67]

thanks altec, if it is a dana 60 any idea on the gears ? top speed is like 50- 55 it will get up to 60 and over but the motor dont like it.

[Altec]

Originally Posted by scikotic67

and also altec what do you mean by combination ?

Confirmation. Simply that I'm leaving it open for someone to correct any mistakes I may have made. Although I'm 99.99% sure it is a Dana-60. You can tell by the casting on the driver side of the pumpkin. Same with the transfercase. It has the vertical casting for a extra brace, and that little "cup" deal on the back side. No transfercase looks like that, and it would be factory until '69 IIRC. The transmission was updated in '68 though. Replacing the SM420, with the SM465. So you pretty much have the last year for that transmission.

But I never hold much faith in what SHOULD be on any older truck... Things get changed so much, factory trucks are a blessing... Well, a curse to me. I can't bring myself to own stock classics. I wanna mess with them to much for that...

Originally Posted by scikotic67

thanks altec, if it is a dana 60 any idea on the gears ? top speed is like 50- 55 it will get up to 60 and over but the motor dont like it.

That I simply do not know. It may have a tag somewhere under the gunk. Otherwise you can try the old "Turn the axle, and count how many turns it takes for the tire to make one complete revolution." Or pull the rear cover. It'll have the ring, and pinion tooth counts on it. Easy to figure out from there.

[67gmcstepside]

Originally Posted by scikotic67

ya the lift is retarded, and the exhaust is junk , the engine compartment needs help, just trying to figure out more on it before i start ordering parts, were can i figure out that its the right motor for the year ?

Your truck is much nicer then what I started with. Nice start. Good luck!

[scikotic67]

ya i misread i thought you said combination not confirmation, ill see tomorrow if I can grab any numbers off the rear end and transfer case, where should the numbers be on the tranny ?

[Altec]

Originally Posted by scikotic67

ya i misread i thought you said combination not confirmation, ill see tomorrow if I can grab any numbers off the rear end and transfer case, where should the numbers be on the tranny ?

Transfercase numbers will be on a riveted tag located on top of the case. Bring a mirror.

Transmission casting numbers are located on the driver side. Although, if I remember correctly they don't really say anything. Where as the SM465 can tell you what it is by the FIRST three digits (465 being a common number lol).

To spot a SM420 the easiest way is the round bottom, and single PTO cover on the driverside. SM465 has a PTO cover on both the driver AND passenger side.

[swamp rat]

Originally Posted by scikotic67

thanks altec, if it is a dana 60 any idea on the gears ? top speed is like 50- 55 it will get up to 60 and over but the motor dont like it.

My guess would be you have 4:56 gears but if you can find the BOM numbers on the axle read this post and do what it says and you can find out.

http://67-72chevytrucks.com/vboard/s...05&postcount=4

Yea it looks like a rockwell transfer case

http://www.google.com/imgres?imgurl=...1t:429,r:2,s:0

[OrrieG]

engine should have a number stamped on the flat pad in front of the passenger cylinder head. Last 3 should be letters like TOK. That is the code that will tell you what engine you have. I don't have the info but was able to trace the donor engine for my truck by doing a google search with the letters in the subject. If the pad is blank the engine block has been decked. There is also a casting number behind the driver head under the firewall, hard to get to and read but it can tell you which engines used that casting number, again using a google search.

Forgot to mention, if it is the original engine the numbers on the pad will match the last 5 or 6 numbers of your VIN.

[Redcap]

That rear is definitely a Dana 60. Gears are probably 4:11 (most common ratio in a D60). Get rid of those front blocks ASAP.

[special-K]

Nice truck! What you have is a top-of-the-line Super Custom K2500. You didn't mention it's a GMC when I replied,they had Dana 60s. It sounds like you have 4.56s.You can run along at 75-80 with 4.10s. It appears to have all it's original drivetrain. GMC didn't use V8s until '68, except some late year '67s. I've never seen anything but a 327 and only on Super Customs. Are you sure those hubs don't turn to "free"? Could you post a close-up of those? I assume it doesn't have a SPID on the glovebox door.At least most '67 GMCs didn't have them.

[duallyjams]

Looks like you have buddy buckets also. That is a nice find for a 4x4.
You can update the front rear to a later model if you want to upgrade disc brakes and a open knuckle.Go with 3:73 gears and that truck will do anything you want it to.

[67gmcstepside]

Its not difficult at all to swap out the axles. While your add it you might want to add PS. It all was straight forward. Everything just bolts into place. I replace both axles and added PS to my 67 GMC over the last summer. Never worked on a 4x4 before and had no issues. The guys on this site are great and will assist with any questions. They talked me through my build.