Mike, I removed the 8.2 rear and swapped in a 8.5 with a 3.23 gear set and stock posi. I also run P215-70-14 tires and the engine sings along at 3200 rpms when trying to run 70 mph, which isn't fun for extended periods! It sure is fun for in town driving however, and those are the same tires/gear I use at the strip to run mid/high 13 second 1/4s.:3gears: I did buy a set of 29" tall 15" tires for road trips to keep the rpms down when running for hours on end, and some 27" tall 15s for the front to even it out a little. I haven't trailered my Buick yet and it's made half a dozen 1000 mile road trips!
I'm planning on swapping out my 8.2 peg leg 2:73 for a 8.5 posi 3:23. Pro's and con's- Love the highway driving with the 8.2 but around town and acceleration it's a dog. My Focus hatchback is faster under acceleration. It's been tested. I'm a stickler for acceleration so I'm tossing the 8.2 for the 8.5 with bigger gears.
Hey guys...Just to let you all know the 8.5 10 bolts do come with 2.93 14 41 gear tooth count if you need a good used set let me know. I have 3.23 also and 3.08. As for the 2.93 to 3.23 switch. seems to me the rear you are dealing with is a large pinion 1.875 diameter. There are NO aftermarket gears for this GS 1968-1970 rear...Unless you have something different in there like a pontiac one. If this buick guru guy has gears please let me contact him I would like to see what else he has in stock for this 10 bolt 68-70 rear. If you can get the gears I would do it. 3.23 will be a very good universal gear. good low end and still good mileage and rpm cruising. Like I said make sure you know the rear diff you are dealing with to prevent a headache. Jim
Here is a list of all the gears that cme in a 8.5 rear.... 2.41, 2.56, 2.73, 2.93, 3.08, 3.23, 3.42, 3.70, 3.73, 3.90, 4.10 4.56, 4.88, 5.13, 5.57 seems the only good gear left out is the 3.64...lol and or something in the 3.50's why they have such a large gap is beyond me. ??? Jim
Jim, The 3.23 set that he has is a good "used" set and he is aware that this is the '68-70 8.2 rear. :beers2:
Jim 3.23 ratio was most common in 68-69 sportwagons.. you might keep your eye out for those in wrecking yards in your area.
Dude there is not a car older than 1990 in our yards... A wagon would have been demo derby long ago. So your saying the guy has used gears or new gears? jIm
Jim, He has a set of good used gears, no new gears. This is the only set that he has for the 68-70 10 bolt. If for some reason it does not work out with the 3.23 set I have my original 2.93's. If for some reason my original 2.93's are not reusable then I have to start thinking about an 8.5 swap I guess. If you were closer I would bring my rear :laugh: to you for refurb but I do have someone local that has a good reputation that can do the job for me. If something does not work out with him I will be contacting you and making a road trip with my rear. :beer
Three hours is not bad. I work in Beachwood Oh which cuts the 3 1/2 hour trip to 3 hour trip. I live 1/2 hour south of beachwood in Richfield. Did a GTO diff for a guy in erie and he dropped it at my work also. Just let me know on either of the gear sets...something is better than nothing. anyone else out there have any 1968 - 1970 gears 3.08 or anything in the 3 series gears PM me you might have some money coming. Jim
Jim, Wanna buy a slightly used 8.2 inch open 2.93 .... LOL My motor is going in soon so I'll be testing out the 8.5 you built for me :TU:
Another option and the best one I've found so far is to run the 2.93's in the 8.5 corporate rear with a 3.0 low geared t400. My first gear is = to about 3.55's now and I still have the 2.93's for driving on the interstate in third gear. Second gear is also a bit lower. Works great!:3gears: :TU: The next step would be a overdrive.
That is what I would do. You should pick up .2~.4 in the 1/4; will deffanatly loose some highway manners though.
2:93 Posi and a 455 is a great combination. You can roast the tires anytime ,cruise and pass other cars like there standing still. The Buick engineers knew what they were doing!
If you want to keep the highway RPMs with 3.23s, use 28" tall tires on the street and 26" for the track.
I like 2.56, poor man's OD. With Buick torque it still has more power than you'll ever need or get away with on the street without landing in jail. (been there done that)ou:
