Hello every one. I have a 79 150 and would like to swap out my rear end for a newer one. I have no clue what the gears are in this thing the tag and any thing else that I could use to Id it has been taken off..
Its a 9" right now hooked to a C6. What would be a good rear end that I could go pull out of a junk Yard?
This rear has really been a pain no one can Id the gears, so its hard for me to get good help on selecting things like cams or stalls.... Any help would be great thanks alot

 

You do not want an entire rear end. You will probably only need to change the ring and pinion, perhaps even add a traction aid, such as a limited slip unit while it is apart.
Either way, you will have to remove the driveshaft, pull the axles, (super easy to do) remove all of the center section fasteners, and pop out the center section.
Once you remove it, you can count the ring and pinion gears and determine your ratio. If satisfied with the ratio, and a visual inspection indicates that everything looks good, then you re-install everything, and you will have performed a decent service, by changing the fluid, and you will now know what you have back there.
You might find that you are satisfief with what you have, and this will eliminate wasting time and money.
Then you can determine your cam, and converter concerns.
You should also know not to get too aggressive on either the cam or the stall converter. Higher stalls produce greater amounts of heat, and will promote softer shifts. Both of these combined will contribute to additional wear on the transmission.
Too much stall and not enough gear will have you below stall on the highway, and this will mean a bunch of heat.
Anyway, stay conservative. Too much can be exactly that, too much.
Conservative will be much better than getting too agressive here.
Good luck with your selection.

 

No tag on the axle bolts???

 

When I had my '84 f-150 I swapped my gears from 3:00 to 3:50 and threw in a posi. What a huge difference! If you can find a 9" pumpkin with a set of 3:50's, I think you'd enjoy those.

 

Well that doesn't sound to hard,
I've looked in to a "9 pumpkin " and they are to much I have a budget =)
Yes all tags are gone. ya I was a little shocked when I started looking around.
How much does it weigh? do I need a jack to bring it down don't want it to crush me when I take it out..

 

Use a jack to gently break it loose from the housing. Just put the jack under the casting near the pinion. After all the nuts are off, jack slowly till it cracks. Use some blocking and plywood and cardboard to "ramp it down" when it comes off, as it will break your arm if it falls on you. 60+ lbs IIRC...

Be sure to have a big drain pan under it when you crack it. Go to lunch or overnight for it to drain, as the gear oil is slow to finish dripping, and there will be plenty left in the housing as well. Messy...

 

you could find a 9in 3rd member at the junk yard with the correct ratio and that would be the cheap way to go probobly in the $50-100 assuming you need to change it once you find out what you have now also a locker is highly recomended

 

Thanks allot guys for your all your help.
Yes I really want a locker, and i'm starting to fear there might be some thing really wrong with my rear end, when I come to a rolling stop I hear a roaring sound coming from the back and also when I put her in to reverse I get this real loud Chunk clang! I've checked the oil level and its fine. But I guess a rear end thats pushing 30 years might need some help. She was a farm truck when I got her.

 

Look at your U joints for the clunk...maybe you get lucky.

I would not put a $50 or even $100 unit in. You're doing all that work, and the odds are, it's no better than what you are taking out, and may be worse. Does yours howl like a wolf at an all night beer party?

Pull it, check the ratio, proceed with care.

BTW, when you clean out your housing, use some rags, carb cleaner or solvent and a stick and push the rags through the axle tubes. Make sure you don't leave debris in there. Especially metal debris....

 

Well its hard to hear over the cherry bombs..... but it is a very loud .. ya I one could say howl or roar.
I had the U joints changed out and it didn't help with the clang when I put it in reverse it not only clangs but also lurches a little its not at all a smooth shift. but when I pull it apart i'm sure i'm not going to be very happy

 

im just saying if he want a different ratio cheap the junkyard would be the place to go

and the clanking in rev could also be the c6 going out

 

I've been doing some reading about Ratios and I under how the numbers work but I cant seem to find any thing about whats a good ratios go with.
I talked to a guy at the auto store and he said 4.10 or bigger. I really have no clue on what ratio to go with..

 

What do you need your truck to do for you? If you're pulling or loaded down all the time, then go with 4:11. A good all around ratio for pulling or just driving would be 3:50. If you want better gas mileage for highway driving, go with 3:00 or even 2:76.

 

No her work days are over. the only work she will be doing is hauling some wood or 4 wheeler maybe stuff when I move but other then that she will be 90% in the city and 10 in the high.. and i'll be upgrading to a bigger engine here soon pumped up 302 or a 351

 

If you don't care about gas mileage....or tires....you'll have a heck of a lot of fun with 4:11's!!!