8-3/4" Purchase Questions

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mickey_bigdaddy

mickey_bigdaddy

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I would like opinions on my best option. I'm going to upgrade my rear end on my A body since I'm installing a big block.

I currently have a correct A body length 8-3/4" housing, no carrier or axles. The perches were cut off previously.

Option #1:
Buy carrier, axels and reweld the perches back on the housing I already have.

Option #2:
I found a 741 A body 8-3/4" non sure grip for $250 on a Duster. It has the SBP. The only advantages that I see here is that the perches are already welded on and I don't need to shorten it. I don't know the year since I believe this owner added it to this car.

Option #3:
I found a 742 8-3/4" non sure grip for $250 on a 67 New Yorker. This one has BBP axels.

I want to get posi so I'm going to have to address that for all of the options and I'm probably going to need new gears since I'm going to have to match with the rest of my new drivetrain. I'm thinking I should go with Option #1. What are your thoughts?
 
I would go with option number one, but that depends on whether you can find all the parts needed to complete the job. If not I would go with option number two and try to find a sure grip
 
Lets look at all of them

Option #1... If you do this make sure it's a straight housing before you even bother welding perches back on. If the guy that cut the perches off got "torch happy" it's possible he warped the axle tubes. If it is straight, weld the perches on slowly. Do 1/2 to 3/4 inch welds at a time alternating from side to side. It's a lot easier to warp a housing than a lot of guys think.

Option #2 may have small bolt pattern axles but if I read it right it's a complete axle for $250? If it is complete it's a great buy as long as it's in decent condition.

Option #3 The 742 case was last produced in late 68/early 69 so there's no way it's original and who knows what it really is until you measure it. I've seen guys spread springs an all kinds of crap to make a rearend fit. If you verify it is a complete earlier C-body axle assy swapped into the 77 it can be narrowed but that'll be another $250-450 depending on labor costs where you live. Even if it costs more it has the advantage of larger brake assemblies than an A-body rearend and big bolt pattern wheels if that's what you prefer but more than likely you'd be able to find a A-body rear ready to go cheaper than it'd cost to build this one.

BTW: not a huge deal to me but you'll rile a lot of Mopar guys saying you want a "posi". Posi is a GM only term. Sure grip is the Mopar term for a limited slip differential.
 
Typo, thanks. Option #3 is a 1967 New Yorker. I fixed the original post.

As far as Option #3 goes, isn't the quality of work just as important to get someone that doesn't hack up the rear end and axles to narrow it? I'm a little in dark on who I would get to do that locally and I assume if they are knowledgeable, they will charge a pretty penny.

I like option #2 but, those axles will be replaced and that carrier will need to be upgraded to a sure grip (not posi, see I learn quick). So seems most of my $250 goes on the shelf in my garage since I won't be able to sell those pieces.

Thus, my logic to just go with Option #1. I'm pretty sure it's a straight housing. The perches still have some of their legs still welded on the housing so it doesn't look like it was overheated.
 
Forgot to add, that I found a 1960 Desoto Adventurer & a 1964 New Yorker with an 8-3/4" in it. I hear the 64 New Yorker has sure grip factory std. But, I can't get the wheels to turn since it's on the ground. Anything special here?
 
I would buy the least expensive B,E or C body housing, weld a backbrace on first then weld the perches on next, then shorten the housing using a jig to align the ends. Next buy Dr. Diff axles and then build whatever pumpkin you want. You can build a pretty stout rear for under $1000.
 
Help me out with the pricing:

Base B, E or C body rear end (non sure grip) = $250.00 (I found a couple at this price)
Dr. Diff 8-3/4" Clutch Type Sure-Grip ("Powr-lok") = $395.00 (out of stock)
Dr. Diff Axle Pkg Stock Length Mopar 5 X 4-1/2" Bolt Pattern = $295.00
Narrow rear end = $250-$400 (gotta think in my area, it will be more like $500)
Brake job, bearings, lube, seals, etc. = $200 or more
Total = $1390.00 to $1540.00

Not adding up to less than $1000.00. Did I misinterpret what you meant?
 
mickey_bigdaddy said:
Typo, thanks. Option #3 is a 1967 New Yorker. I fixed the original post.

As far as Option #3 goes, isn't the quality of work just as important to get someone that doesn't hack up the rear end and axles to narrow it? I'm a little in dark on who I would get to do that locally and I assume if they are knowledgeable, they will charge a pretty penny.

Your right, if it isn't done right it ain't worth a hoot. I have to drive 40+ miles to get it done right.
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I like option #2 but, those axles will be replaced and that carrier will need to be upgraded to a sure grip (not posi, see I learn quick). So seems most of my $250 goes on the shelf in my garage since I won't be able to sell those pieces.

Thus, my logic to just go with Option #1. I'm pretty sure it's a straight housing. The perches still have some of their legs still welded on the housing so it doesn't look like it was overheated.
Click to expand...

Agreed
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mickey_bigdaddy said:
Forgot to add, that I found a 1960 Desoto Adventurer & a 1964 New Yorker with an 8-3/4" in it. I hear the 64 New Yorker has sure grip factory std. But, I can't get the wheels to turn since it's on the ground. Anything special here?
Click to expand...

The 60 rear is useless because it has keyed axles and brake hubs and the housing ends are different so you can't use newer standard flanged axles in it. If the 64 does have a sure grip it would have to be the clutch type and will work in any newer case but it'll most likely need rebuilt so unless you can get it real cheap your not getting much, IMO... The 64 might also have keyed axles. Can't remember exactly when they switched over but it was some time in the early 60's.
 
'64 New Yorker has the keyed axles. I forgot to mention that.

But, if it's 741 carrier (pumpkin) has the sure grip can't I just take that and use it?
 
Out of the frying pan and into the fire.

IMO, The 9 1/4 is a pile of junk.

There are chassis shops/rock crawlers all over the DFW area. If shops in LA will shorten a rear axle for $150, they should be the same range in DFW. Moser is an option, 145 + shipping each way.
 
mickey_bigdaddy said:
Started new thread:

http://www.forabodiesonly.com/mopar/showthread.php?t=276716
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Since these 8-3/4 rear ends are either elusive, overpriced or require too much investment to make what I want, I've decided to narrow and upgrade the 9-1/4" I just acquired for my Dart Sport. I need to find out the best way to make a 9-1/4" a suregrip. Anyone have a thread they can refer me to? I've done search to convert a non-suregrip to a suregrip and I can't find one.

Can't I just add the suregrip to the non-suregrip?
Click to expand...

You'll pay for new axles for the the 9 1/4" and pay to have the housing shortened. And you will pay for a new 9 1/4" sure grip and probably pay for new gears.

IMHO, all you are getting from this over the #1 A-body housing you have is the center section housing and the perches are welded on.

Do you not feel confident on welding new perches on your #1 A-body housing? Do you have a price from a local guy that will do that for you?

Thinking out of the box... what about buying the $250 a-body rear (drum to drum?) and selling it for $550. Maybe take $450 at lowest. Should sell fast for $450? Then take the $200profit and buy axles for your bare housing.

OR.... buy the $250 rear end. Put the axles, brakes and center section from $250 rear in your bare housing w/o perches. Sell that for $400.... Put $150 towards new BBP axles. Find 10 1/2" 8 3/4 backing plates ($40-$50 or junkyard maybe). Buy new drums and brake parts. Find 742 center section core (any gears) have new sure grip and new gear installed.
 
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