Anyone on here ever done or know what is involved in doing an axle conversion on a 69 Wildcat, i think the wildcats are C-Body. I need to convert it either to a GM 12 bolt, Ford 9", or Dana 60. If you know, which one would be the easiest to convert to, and which ones are easy to find? thanks
The '65-70 Impalla 12 bolts will not work without rear frame modifications in the Wildcat. Coil spring mounted Dana 60 would even be a bigger nightmare. In the same position, a nodular case built 9" Ford would be my choice. Designing a correct geometry single upper control arm mount to weld onto the 9" housing will be the hardest part. Mounting the Buick 9 3/8's lower control arm mounts should be rather straight forward. Looking for a similiar width factory built 9", is as simple as reviewing what width 9" Ford rears were built. For most 9" housing builds, I usually cut down 9" truck housings & jigweld hsg ends & order new axles. Most of the narrower factory built 9" housing bring a premium, & you will not need such a narrow track r/e for such a big car. :3gears: Roger
if i got an axle that was about 2" longer than the stock buick rear, would it bolt up the same? also, would the tire bolt pattern be the same? because i think if i get an axle 2", or close, longer with my tire offset i could manage to fit 10's in her. and that would be sweet! and help with much needed traction.
Steven, The problem you're going to run into is there is no easy bolt-in rear other than a few years of Buick 9 3/8 rears that have all the provisions to bolt right into your Wildcat. Might raise your car up & look at the odd single upper control arm mount on the r/e, then look at the lower control arm mounts. This design was not shared with other division GM big cars of the era. For simplicity of fabrication, the nice thing about the Ford 9" one has a lot more area to weld bracketry to. Width wise, I don't currently have a '69-70 9 3/8 Wildcat-Electra rear here to measure. There should be a bare Ford 9" housing that is similiar in overall width but this is not what one should look at 1st. The problem to adapt the Ford 9" housing, one will have to figure how to correctly locate a fabricated single upper control arm mount to the 9 inch housing. This will have to happen 1st, then one can take into account where the axles flanges need to be, so tires & wheels fit correctly. Most likely, a wide 9" truck housing's axle tubes will need to be shortened, axles will then need to be shortened & resplined, or replaced with custom versions. Hope this helps... if you can provide pics & overall measurements of your 9 3/8 rear, I'll measure the 9" truck & van housings, I have in the racks, & try to narrow down what the best starting point would be if you want to go 9". :3gears: Roger
Roger - Would a later model Impala/Caprice style 8.5" rear work in some of the older big cars? I believe they both have the 5x5" pattern. These are 30 spline rears for the 91-96 cars right?
well, where should i measure? and i bet here will be some fabrication going on to fit the rear into the car, but they say the buick wont hold the power im putting into it. im searching around for some custom differential places around my area.
The later Caprice/Impalla/Roadmaster rearends will bolt into a '73-77 A-body, as long as it's not a '73-77 A-body wagon. Will also bolt into '77 + GM B series. The 5 on 5 bolt pattern can often present a problem, mention that though some '73-77 A-bodys actually used 5 on 5 bolt pattern. As far as any later coil spring rear being an easy bolt-in fit in earlier coil spring big cars, I've yet to see that work. The problem one will run across on the pre '71 big cars, is nearly each GM division had it's own axle division. So much autonomy in design, as well. This makes it tough to mount one division's rearend design under another divisions chassis. It can be done, but often will require serious study of the two different chassis, & frame mods. :3gears: Roger
Steven, Considering a 9", the main things that would help would be pictures of the single upper control arm mtg area on the 9 3/8 housing, along with overall width measurements & some rough measuements from each axle flange to the single upper control arm mount. Many more detailed measuements woul be needed for fabrication, but the above few, can help narrow down which 9" core housing would be easiast to fab off of. Looking for a qualified 9" housing fabricator, ck with local racecar fab/chassis shops. :3gears: Roger
Overall axle flange to axle flange width can be relatively easly measured with rear frame being supported by jackstands & tires & wheels removed. Unhooking the rear shocks will often allow the rear to hang down enough to get the other measurements along with unobscured pictures. Also doesn't hurt to have a helper to propperly position the opposite side straight edge & end of the tape measure. Roger
that isn going to happen for awhile :laugh: my jack is caught holding my tranny up, the thing broke my tie downs that were holding it up. probably the only thing i can measure overall is the axle tube length, the "hog's head" length, and maybe the length between the backplate's.
Sounds like that floorjack is busy ou: Get it loose, feel free & ck back in. Rebuilt my second string floor jack last night... needing both of them today, haing TOO much fun :rant: trying to figure what's up with the transaxle in my diesel Volks stationwagon. Best "going to the sticks" partschaser I've ever had, I'm just not an import mechanic. :3gears: Roger
This is organization :laugh: not sure if you can see the letters in the first pisture, but the others are bigger. Just in case: A=the inside of the backplate on the drivers side B=On bracket where the lower contral arm mounts drivers side under axle C=Where "Hog's Head" ends and converts to axle tube Drivers side D=Where "Hog's Head" ends and converts to axle tube Passenger side E=On bracket where the lower control arm mounts Passenger side under axle Fthe inside of the backplate on the passenger side and between the insides of the brake drum lips, while mounted, is 54.5" A-C=19" A-F=56" B-E=45.25" C-D=18" Not sure if this helps in any way, but thats all i got for now. and there are 2 upper control arms i see. does this change anything?
Stephen, Glad to see the '69-70 big Buick housing has two upper control arm mounts. Was under the impression ou: that particular housing had only one goofy upper mount. Builder/chassis shop fabrication of a 9" housing should be much more straight forward :beer Before addressing axle flange to axle flange dimensions, it would be smart to figure how big a tire wheel combo you can get in the rear wheel well & then work from there. Believe I responded to you in an earlier post, & if you truly are installing a big Buick 650-700 hp & I'd bet close to 600 ft lbs of torque, that kind of power will do no good, unless it can be put to the ground. You're at the point, I'd check into what other late '60's Buick & Olds big car owners have done in similiar heavy car builds. Will sidetrack a little... In my '63 LeMans "streetcar" project (a lot lighter car, but with little more hp & tq), I picked 10.5W's as tire of choice from the get go. Though the sidewalls are marked as 10.5, they're actually a little over 12" wide on the rim. The 10.5W's required minitubbing, which was expected. In a full frame vehicle, rear frame rail notching or relocation is usually a must. Tire/wheel size requirement have to be addressed before r/e & rear suspension can be sorted out. A good local chassis shop can walk you through this. :3gears: Roger
i think if i get the dimensions right on the axle, if i dont i can always use a spacer if its under, i can manage 10's in there. my tires are 8.5's, measures 9" at the tread, i have 1" behind the tire and approx 2.5" on the outside. plenty of room. if need bee i can bend the lips of the fender in where it might come in contact, giving me about another 1.25". would it be wise to move the axle back an inch or so to create more room for the front of the tire? mine are 30 tall and i have about 1.5" in front, plenty in back. also, could the fab shop just fab control arms instead of changing the differential? that way i can re-use the differential and switch control arms when i want to change diffy's.
also, checked it and its an open 3.07. its where the book says, but not where they board told me. also the stampings arent like the book says, they said it should be 2 letters and 3 numbers. i have 1 letter (D) 3 numbers, and then another maybe 5 inches away a G, and what i guess would have to be a P before it. theyre not very good stampings though. so where am i going to find this 9" carrier i need?
Stephen, Without providing the right dimensions, all I can suggest is you could aquire a 9" Ford truck or van housing. That's what I usually use to cut down & weld ends on. Planning on eventually going even quicker, skip the mild steel housing tubes & go to a source who jig welds the hsg to chrome moly axle tubes. Have such a source I use outside of town. On post #17, am afraid, that is beyond the scope of what can be replied to without having the car in front of me. While I have run across G-body custom length control arms that would better center a large tire in a wheel house, there is no such readily avail fix for your Wildcat. In order to center the tire, & get instant center & pinion angle right in your vehicle, you are going to have to break down, & take the car to competent chassis builder/rearend fabricator. The exact tire & wheel combo you plan on running are going to need to be in hand... An experienced chassis shop will scale the car, do all measurements, consider the tire/wheel positioning, give you a ball park quote as to what a HD custom built 9" Ford r/e will run, including whatever rear chassis work will be needed. Hope this makes sense. Got Posi? :3gears: Roger
