differential ratio listing [Archive] - El Camino Central Forum : Chevrolet El Camino Forums

: differential ratio listing


Allenbase
04-22-2003, 11:32 AM
does anyone out there know were I can locate a list of rear-ends and there ratios that would fit in my 79' Elco. I have dropped in a fully bored, stroked, balanced, blueprinted 383 small block with a 700r4 trans. Would like to play with rear end ration to compensate for the extra gear.

Mecheng
04-23-2003, 06:15 AM
You're pretty much restricted to '78-87' intermediates of the GM family. Nothing else is a bolt in. I did see a guy bolt in a 70 Monte Carlo 12 bolt. It must have been awfully stressfull on the upper links and U-joints cause it's not suppose to fit.

A real find would be a 84-87 Cutlass 442/turbo Regal 8.5" rear end availble with 3.42/3.73 gearing. See my album (http://elcaminocentral.com/modules.php?set_albumName=album19&op=modload&name=Gallery&file=index&include=view_album.php)

Short of that look at the junkyards for an overdrive equiped intermediate. Its more like to have lower geared rear end. Count wheel driveshaft turns vs one wheel turn to get the ratio assuming both wheels turn if only one wheel turns multiply your result by two. 7.5" ratios are 2.29,2.41,2.56,2.73.3.08,3.42,3.73,4.10 (S-10)

If you're only looking for a gear set then go straight to the S-10s

87ElCamino
04-23-2003, 07:17 AM
I did see a guy bolt in a 70 Monte Carlo 12 bolt. It must have been awfully stressfull on the upper links and U-joints cause it's not suppose to fit.

South Side Machine (http://southsidemachine.com/index.shtml) makes a kit (part #1328) to install a 1964-1972 10 or 12 bolt rear end into "G" body. The kit includes the upper and lower control arms, spring seats, and lower shock mounts.

Mecheng
04-23-2003, 11:38 AM
Good point Ernie. I studied this a while back and new it could be done if the arms were offset and spring pads and shock mounts rewelded. The cool cat I mentioned used a BFH and the axis of the pinion was not were it should have been. I forgot about the springs, that looked pretty cheesey too. In all it was a dangerous bolt in!

SSM's kit and a 64-67 12 bolt rear end would be pretty close drum to drum. My not need many mods

tinkerer
05-03-2003, 02:19 PM
I had installed a 70 12 bolt ina 78 malibu using the stock arms. It never gave me any problems and handled my 350/4 speed with no problems. It might have been dumb luck, but it worked. :D

Mecheng
05-05-2003, 11:24 AM
Interesting. Why would anybody pay upwards of $750 for G body 8.5" when they could "bolt in" a 12 bolt rear end. :?

87ElCamino
05-05-2003, 12:29 PM
Why would anybody pay upwards of $750 for G body 8.5" when they could "bolt in" a 12 bolt rear end.

Have you shopped around for a decent 12 bolt recently? I can't remember when I last saw one for sale. I see more 8.5" at swap meets.

:mrgreen:

workNprogress
05-06-2003, 10:26 PM
I know it was posted but i can't find it now, on active hunt for posi rear end and saw someone had said some malibu wagons had posi's, please retype donar list, or a link.


thanks
robrhino

theelcaminofactory
05-07-2003, 07:29 AM
12 bolts are becoming quite rare, and if you did find one, and went with the South Side Machine Shop setup, there's still welding involved. The 8.5 is a simple bolt in swap.

OddsNEnds
06-20-2003, 10:43 AM
Be sure to check your driveshaft length when swapping rear ends in G bodies.

To swap in a 8.5 you will have to shorten the driveshaft by 1 inch. You risk either cracking the transmission and/or blowing the rear trans seal.

I swapped one in my '79 Malibu, it was an extremely tight fit with out the driveshaft shortened. Still haven't shortened it yet, but, will be doing it this summer.

I was fortunate, I got the rear end from a Buick T Type and paid only $450 for it. I hear they go anywheres from $600 to a $1000 usually.

OddsNEnds (http://www.hawaiianflavor.com/Malibu/malibu.html)