I have a '66 Skylark with a 455 and I'm about to swap in a 8.2 posi rear that I got out of a '65 'lark with a V-6 of all things. This is temporary until I can build a stronger 12 bolt but my question is how long will this rear hold up at the strip with drag radials? I'd like to race it a couple of times this year but feel it would be a waste of time with street radials. So what do you guys think? Is anyone running drag radials with their 8.2?
heres a thread i posted last summer . ive twisted a number of 8.2 axles in my 66 , but never as bad as this one out my dirt track car from the drivers of a '67 gs340 i ran a few years ago http://v8buick.com/showthread.php?t=81027
Depends on how quick the car can 60 foot, & how the 8.2 rearend is being torqueloaded. Lighter automatic footbraked A-bodys are typically less hard on r/e's than same weight 4spd cars. Still, with a strong 455, you are past the limit. The problem the gray iron 8.2's have, is lack of pinion support. The BOP 8.2 pinion is small in diam & under high torque loads, when one can get the rear suspension to hook, something has to give. Simple physics... inside the hsg, the pinion is trying to rise in respect to the ring gear, & with flex in the pinion area, often, a shattered ring & pinion will result. The weaker the casting in the pinion area... well the results have spoken for themselves going on 40 years. Funny thing is, with a ton of torque, many unimformed folks, have just run out & pony'ed up for stock 12 bolt posi's... only to throw 500 fts of torque at them & shatter brittle spider gears & twist & break light duty 12 bolt axles. Not that smart. Going to upgrade to a 12 bolt, HD 10-17 spider gears & good axles are a minimum. Back to the 8.2's... as factory torque levels rose, ck out what Buick, Olds, & Pontiac engineers were up to. GM division engineers weren't trying to make the most durabile r/e's ever, instead they were merely trying to keep ahead of warranty issues. -The beginning... '64-66 Buick 8.2 housings were cast of gray iron & had only one strengthening rib per side. This casting design made them the weakest of all bolt-in axle 8.2 rears. Olds also shared this r/e casting in the '64 & in '65's I've double ck'ed, even 442's. - Quite a few 442 guys have noted that highest hp/torque '66 442's received Pontiac version of the 8.2. When Olds started using them, I am unsure. Pontiac's converging 2 rib gray iron housing was stronger, but time has shown this hsg design will not hold up to heavy low 12-high 11 sec drag strip use. Just have rebuilt way too many of these that friends & customers have blown up. For strong street/strip use, I won't build them. - Torque levels were rising & for '67, Pontiac introduced nodular hsg 8.2's for use behind Pontiacs strongest 400's. By casting out of nodular iron, pinion area flex was minimized, but even the nodulars just don't hold up well in high torque drag raced heavy A-bodys. Today, the nodulars are a resto piece. -Olds introduced the type "O" 10 bolt in '67, & Buick introduced their improved Buick8.2 in '68. Both were deemed adequate for use behind these divisions strongest stock engines. Today, short of high point restorations, both have fallen out of favor. Got Posi? :3gears: Roger
8.2 You'll probably be just fine. If it brakes at least your axles will be intacted. Most damage and brakage will happen in the 60 foot area. not as much spped there. Have fun and good luck. Test it out on the street first for safty if it is totally new to the car. as with anything work your way into trust. Jim
What is an 8.2 appropriate for? I am working on a 65 skylark gran sport automatic worthy of a frame off. It is a nice matching car except for the rear end which is open. found a nice vintage 8.2 3.36 rear. I intend to rebuild the motor and add a factory 2x4 set up. I will be happy with a mid to low 13 car. mostly street applications. the occassional strip. Can this rear end hold up? Is the 8.2 issue only really a concern in the heavily raced 12 second or lower cars? I want to spank gto's and mustangs on the street. thanks, steve
Thanks for the responses guys. As I said, this will only be for maybe 3 trips to the strip this year. By next summer I hope to have the 12 bolt with all the good parts and 3.42s as well as the built 200R4 installed. For this year though I think I'll start with street tires and if its just too silly trying to get it moving I'll bolt on the drag radials. I still won't be leaving off the converter but I'd like to be able to punch it off idle and not blow the tires away. Like you said Jim, at least if I do break an axle, it will stay put. I guess we'll see. :grin:
8.2 10 bolt You'll be fine as long as you put some respectable parts in it . Just make sure whoever builds it does it right. Pattern backlash etc. Use newer parts in it if you have the money . They are much improved from the older stuff. Casting are ussually stronger and just plan designed better. If you need any parts or more advise check out me at wwwjdrace.com. it is up and running but the store is still having pages added everyday. Take care hope you visit soon. Jim
I got 10 years out of mine before I snapped an axle in half and broke the posi unit, but my GS wasn't that fast (12.70)(3860 lbs) so it depends o No: Randy
I'll be very happy if mine runs a 12.70! :3gears: 425 to 450 hp estimate, th-400 w/ 3000 converter, 2:93 gear posi, drag radials (?) in a heavy '66 'lark convertible with air, power windows and power top. I'll be happy with 12.90s with this set up.
not sure, whats my options So, you are saying it is possible to build a BOP 8.2 strong enough to withstand 500 ft. lbs.? Looking at the best options, rebuild, gm swap, or 9 in? All with cost in mind obviously. I was told by D&R driveline last night, no way no how. Please chime in.
8.2 strength I have the impression you are more of a street bound vehicle. If your going to use slicks every weekend and over 3500 stall, trans brake, etc. which to me sounds like a race car. don't bother. A street bound car will have no trouble with a properly put together 8.2 rear with 500 horses. The street provide no traction on high torquey vehicles. So when there is no traction there really is not much strain on the rear...because the tires will brake loose so quickly. Long burn out machines require good components set-up to specs and new bearings with the PROPER FLIUID level keep at all times. This is the biggest problem the heat and lack of lubrication to the needed parts in the rear. Look what happens to the tires when you bake them. 25-29 inch tall tires . Now look at the size of the bearings 2-3 inches in diameter...??? Do you get it now? The fluid is the only thing that keeps them alive. Get a good unit Eaton or Auburn good name brand gears Motive Yukon Richmond Us Gear etc. have them set up at .005 -.008 Backlash get a good pattern on the ring and pinion put them new bearings in and seals...And get having some fun. Pretty soon you won't be able to afford the GAS!!!! ou: o No: :3gears: Take care. Check out www.jdrace.com for more questions on rear diffs and selling stuff. Sign up is FREE of course plus you can check out the differential store too. Jim I have a couple of GREAT EATON 8.2 BOP posi also if you need...NO BOX sales 429.99 for a 3.36 and up unit. 3/8 or 7/16 bolt sizes 20.00 bucks more for the 7/16 it has to be machined for the bolts.
I will be running ET Streets most of the time, but yes street pounding non-the less with the occasional trip to Martin for some bracket racing. I have a 2500 stall right now. I am not too educated on rears but I do see you are selling some product. What would it cost me roughly for all the necessary parts for this rear? Thanks for your time.
product goods Well I need to know what gear you plan on running. What are your intentions with the car? I would suggest the 3.55 gears as a great all around ratio. What tire size...height in inches. A rebuild kit with bearings Posi unit. Who is building it? Might be better if I just put it all together and ship it. They all you need is brakes and I know it is set up correct. Then see what it holds up to. lol. Jim Please it is probably best we talk about your needs live. phone etc. email me at mitschke454@earthlink.net or 1 216 464 2313 x240 weekday 10 - 5 est
location I see you are in michigan... I actually have a guy coming down to pick-up some 4x4 parts with in the month... We might be able to hitch a ride with him back to Michigan and then you can pick it up from him. Just trying to help anyway I can. I think he is north of detroit ..st.clair area...??? With check to be sure. Jim
