Rear end fit questions

Tim Schroder

Tim Schroder

Member
Wondered if anyone had some input on putting a 12 Bolt posi from a 66 chevelle into my 59 Biscayne. I was just going to cut the mounting brackets off of my 59 donar car rearend and transfer them to the 12 bolt. But after doing some research maybe buying a 4 link conversion kit to mount the rear end would be a better way to go. Anybody done this type of conversion out there. Any suggestions or comments would be appreciated.
 
Windingout

Windingout

Active Member
Supporting Member 2
I have a 63 impala with a 12 bolt in it. The conversion was done by the previous owner so I can describe what is there but I have no detail on the exact parts that were used. They used the lower spring mounts/ control arms from the Chevelle donner car. They appear to have bolted right in place without modifiying the 63. The upper control arms are adjustable round stock with hime joints on the frame end. The connection at the rearend are stock Chevelle and are welded at an angle to align with the stock 63 frame mounts. They are mounted to the cast tabs on the stock housing. It has a 1 piece drive shaft which required a modification to the lower plate of the tunnel. This allows up and down movement of the drive shaft caused by spring action. I bought this car as a project and have not dtiven it yet to see how the set up works. It was a drag car and was raced with this set up so it must have worked. I can not even give you pics yet because the car is in storage all bundled up. I can not remember what was done with the pan hard bar. I have moved to a new house and am building a shop to work on the car. When I actually get to working on it I will send pics. Hope this helps.
 
D

Don Jacks

Well Seasoned Member
Supporting Member 3
Well Ken,if the upper arms are mounted to the factory "ears" on that 12 bolt housing,the pan hard rod would not be needed due to the angle of the upper arms.
 
4speedman

4speedman

Well Known Member
Supporting Member 2
I have a 66 12 bolt housing in one of my cars and it works good .I did as you are planning and cut the brackets off a doner housing and added a second upper control arm.As you problery already know the 66 67 housing is one inch narrower than the 68 and newer housings and works good in our cars.With that being said i did mine years ago before there was the 9 inch housings ready to bolt in and with the axles included were available or at least i didn't know about them.The 12 bolt chevelle posi would bring a good price and go a long way toward the 9 inch setup.
 
Tim Schroder

Tim Schroder

Member
I finally had a chance to pick up the rear end and was wondering if someone could confirm what I have here. Its a 12 bolt rear which came out of a 66 Impala SS, the numbers that I have found are 3852980N on pumpkin, on the axle there is a DH 0208G and then E stamped underneath it. I pulled the cover and the ring gear and pinion have a46 stamped on them, the ring gear has 43 teeth and the pinion has 14. I have done a little looking online and the results have varied a bit but I think its a posi with 3.31 gears. Anyone have some opinions???
 
4speedman

4speedman

Well Known Member
Supporting Member 2
14/43 makes it a 3.07 ,check how wide it is compared to your original housing, the 66 housing i have is a chevelle housing the impala is problery wider and may be a little to wide for your car.
 
pvs409

pvs409

Well Known Member
Supporting Member 11
Original rear end housings are 60 inch flange to flange ( were the backing plates mount).
To use large tires you might need the housing to be 58 inches + transferring the control arm brackets as noted above.
Also dual upper control arms I think are mandatory.

The 58 inches I found was the width needed for decent size tires to fit under stock wheel wells, if you are changing housings..

I decided against the expense - $2500 to $ 3000 for a bolt in Ford 9 inch with dual upper control arms ( or the ability to modify/ welding on a housing to fit + other posi improvements ), since my 500 HP 409 was 95 % street driven. I added girdles on the posi rear end, dual upper control arms on the stock rear end housing and eventually better axles( to date not needed). I was offered a 12 bolt to purchase and turned it down - to much additional cost for a street driven 62 SS 409. I have had at least 20 - 1/8 mile and 1/4 mile runs - zero breakage -- I do not use large slicks.........
Switched to 3:36 posi from 4:11 posi for low RPM at 65/70 mph on highway( I have a Muncie 4 speed with 4th gear as overdrive).

Paul
 
4speedman

4speedman

Well Known Member
Supporting Member 2
Yes the rear end gearing can get pricey.Just to show how things have changed the 66 chevelle housing i have i bought for 10 dollars back in the 80s and you could find them without any problem.
 
Tim Schroder

Tim Schroder

Member
I measured the 2 rear ends today and the 12 bolt is only 2" wider so I should be able to make that work. Does anyone have ideas what type and size of wheels work with these cars. I dont want drag slicks but just a decent looking rim and tire for cruising around.
 
409newby

409newby

Well Known Member
Supporting Member 11
I have a 65 Impala and it was advertised as 2 in wider 2 in lower and 2 in longer than the 64 models so the 2 in wider sounds right :winner
 
64chevydude

64chevydude

Well Known Member
Supporting Member 1
Theres an story on this swap in an old super chevy. I have at home but im not home. Ill post it tonight
 
64chevydude

64chevydude

Well Known Member
Supporting Member 1
Artical is backing plate to backing plate,quick performance is going wheel mounting surface to wheel mounting surface. Add 2 -3 inch brakes to that 54 puts you at 60. If i had to do it again i would go 9 inch ford. Stronger,easyer to swap gears, looks more like the stock rear.

Steve
 
models916

models916

Well Known Member
Supporting Member 7
That article is wrong in a lot of ways. 68 Nova 12 bolt is NOT a bolt in. It's a leaf spring rear? The 64-72 A body rear is the right width but the lower arms are not at the correct angle and the stock lowers won't just bolt on. Stock uppers also won't fit. The 64-72 rear is triangulated both upper and lower.
 
You must log in or register to reply here.
Top