1951 Buick... rear end

so my 51 special is almost ready to be turned on with its original straight 8 and the modern 700R4. this weekend i want to start searching for the right rear end at my local junk jards. Scotch had suggested an '82 or newer GM F-body rear end. im not too familiar with these. can someone please give me some tips on what cars first of all to look under , and then what to look for in a rear end . seriously how can i tell before i go taking it of a car and buy one, if it has posi, what gear it has in it, and if its any good?

any advise or tips would be greatly appriciated. btw, the buick came with springs, however i had already switched it to airbags, so the new rear will be moded to use airbags.

thanks,
Yaril

http://www.jalopyjournal.com/forum/showthread.php?t=98283

 

79 to 84 Bonneville. It's the right width, and the original wheels will fit.

 

the 700r4 is overdrive and the 79-84 bonne is not . while it might be the right width your high gear would be useless. you need to get the overall width that you need and go shopping with your tape measure. the posi deal is a stretch. you need to ask youself how bad do i need a posi. more important is to get the right ratio to work w/ the 700r4 probably around 3.50. a ford 9" might serve you better as you can change 3rd members to get the right ratio lots of ford pu,s in the 70,s-80,s had 3.50 gears.

 

Actually the Bonnevilles were available with a 200R4, and a 3.42 rear gear.

 

I used a seventy Old's in my fifty three Buick and a Cadillac in my Fifty Buick, the Cad is awesome, no worries. Spring perches are another deal, be creative, mine is air bagged in the rear only and it works cool. Good luck, Rags

 

good deal rick, i was looking for something more common. ill check the yards and keep that in mind. i would love to see some pics of that install.

 

good info on the bonneville rear. what was the first year for the 200r4 trans. i know the camaro had their first od in 82.

 

82 also. And it's not Bonneville only, some Olds, and Buicks had the same rear.

 

I'm running a 1968 Mustang 9" rear end in my '51 Buick. Works great, and was the right width. Brake parts are super easy to get and inexpensive too!

 

went to the you pull-it and found that the 82 and newer F-body were too wide. measured about 6 of them, even measured newer ones and a 70s camaro they were about 4" too wide.

found a 79 monte carlos that had the correct width, obviously not overdrive equiped, but i plan to change the gears as per my calculations for what speed and rpm i want to do. bought it complete brake drum to brake drum with e-brake cables had new pads on it and got the trailing arms too. the arms are angled so i will have to cut off the factory braket and either reposition it or make my own, however the arms are 19" which is perfect from center of rear dif to where my X chasis meets the side rails. ill post pics as soon as i clean it up some and cut some brakets off that i wont need.

 

question... please consider that i am setting this up at my ideal ride hight. i am using airbags so my pinion angle is going to move, but i am setting it for about 2" ground clearance (rear drive height).

in cutting open my chassis box frame to insert the trailing arms (i will reinforce the sides later), i came across 2 posible positions to mount the 19" trailing arms.

Scheme A involves more cutting to slide the arms further into the chassis. In order to center the axle mount on the center of the axle.

Scheme B does not require additional cutting. However the axle mounts are further back than the center of the axle.

which of these is "correct"? the drawing is done to scale considering 19" trail arm length and 10" travel distance. does the axle rotate or stay perpendicular to the trailing arms during movement? im using standard trailing arm bushings.

Thanks!