Hi all! Just found out my 71 GS Stage1 has an O-type axle with 3.08 posi. After talking to the owner who restored the car in the 90's he mentioned the mystery of the 12bolt (cover) axle. Car has never been in an accident (all sheetmetal original and straight) so that would have not be a reason for an axle change. The axle has code SD with date code 17th October 1970 (maybe also 1969?). This GS is a Fremont built Stage 1 with the OW tranny, built date is 3rd week of December 1970. Anyone out there who knows where I might find a LWB axle that this car deserves to have?
A lot can happen to a car in 53 years. Hard to say why it was swapped. A longer driveshaft was needed for that O-axle,so when you swap to the 8.5”,you will need to address that. As far as the LWB rear,I acquire them occasionally,but nothing right now.
Why do you think the Early 1971 would come with a 8.5 instead of a 12 bolt olds? If they were laying around AND since there was a 1970 striker in GM this car may have come with the 12 bolt olds rear... As long as the car was a very early 1971 I might have happened. Chassis really did not change so rears were interchangeable Jim
I do understand that 1971 and 1972 are suppose to have the 8.5...BUT very early cars sometimes get this stuff done to them so GM does not have to eat the 12 bolt olds rears. They do it all the time in History.
By the way the way this Buick site is sucking as far as speed up loading goes... All other sites on my computer load fast...NOT THIS ONE. What gives?
I was thinking the same - Especially from Freemont. I'd be suprised if it isn't orig. Been issues w/server upgrades. Couple threads on it. Sometimes super fast & other times...
I say no way. Not early enough. It would need to be an early September car to make it more believable. The production of the 12-bolt O-axle had already ceased 6 months before that.
That sounds indeed most obvious they changed the axle at some point. BrianTrick please think of me when you run into a 3.42 LWB axle with correct driveshaft
The original rear could have even been defective and replaced,or maybe it simply wasn’t a posi. Who knows. I’d also be curious to know the casting date and finish date on the O-axle. The casting date is on the passenger side of the pumpkin,just back from the yoke. The finish date will be one of two places: stamped into the top of the cover,or stamped into the pumpkin,just to the left of the cover,at 9:00.
