Buy the Riv GS, switch rears and sell off the car or buy the $500 67 parts car if it has a posi. https://sfbay.craigslist.org/sfc/cto/d/1967-buick-riviera-gs/6392555733.html https://houston.craigslist.org/cto/d/1967-buick-riviera/6392596036.html
Ok I found a lesabre ok I found a 1970 lesabre rearend, what are the next steps. All of this is new to me so I’m asking questions
A 70 LeSabre has a Buick only 8.2 rear end. It would need to be a posi from a 70 LeSabre 455 in order to interchange with a 67 Buick only 9 3/8. And if you find a 70 Lesabre 455 rear, it may or may not be a posi. If it has standard gear sets, they will be a 2.78 ratio. I guess you current gear set ratio is 3.07. Consider whether the posi carrier for 2.78 gears will support a 3.07 ratio without modification. Ask one of the rear gear experts I referenced.
Take a look under your car and see the rear suspension- traction bar, spring mounts and lowere control arms are unique to the Riviera. The LeSabre has the traditional 4 link type suspension - so it will not be a bolt in. The gears themselves should be compatible. I did the opposite from you and took 3.42 gears out of a Riviera rear and installed into a 67Wildcat. So the posi gear carrier and gears are the thing you need to find. Have patience, they will show up.
Ken, Again...the LeSabre HOUSING will not bolt into your 1967 Riviera. The Positraction CARRIER (the part that holds the ring gear) from a 1970 LeSabre 455 might, depending on your gear ratio versus the donor car. Devon
A LeSabre 455 is a 6000 series Buick. A plain LeSabre is a 5000 series Buick. So ask the owner for the second digit in the VIN. The second digit in a LeSabre 455 is the number 6 while a plain LeSabre with a 8.2 rear bears the number 5 as the second digit. A plain LeSabre will have a 350 cid engine while the donor car you seek has a factory 455 cid.
That’s the key word patience, lol alright I have no choice but to be. Yeah peg leggin it doesn’t cut it
To summarize, Find a big Buick that has the posi tag. If the big Buick donor car is a Riviera you can swap parts BUT Rivieras are different. I know this as FACT. I have a 67 Riviera Posi Rear end under my '70. I pulled the drive shaft and full rear end. This is because the rear flange is different. Otherwise the option is to pull the carrier and gears out of the donor Riviera or non-Riviera model. Unrelated, I wanted to weld in a frame support (non-critical) because mine was bent. I had the same section removed from a '69. The '69 does not even come close in dimensions - but it looks the same.
