I'm trying to find out what way to go with my 63 nova rear end Has 327 engine 375 hp 4 speed trany Any body may give me advice to go 12 bolt or 9inch and what gears I have 10 bolt with 3:08 want to use street but also some track Posted using the Full Custom H.A.M.B. App!
I put a 57 ford wagon 9" rear in my 62 Chevy II. Fits pretty good...but I did a few other modifications to the car.... running 3.25 gears now, but may swap in some 3.70s since I put the bigger diameter tires on it
9" gives up a few % efficiency to get a lower pinion gear, and thus driveshaft.. 12 bolt is maybe not quite as strong, but it is Chevy......
Mine is 5" but some girls like it that big around. Unless your 10 or 12 bolt is a posi spring for a 9". The cross pin in the GM rear is really easy to spin with an open rear. Your gear ratio depends a lot on the usage of the vehicle, if I was building an around town vehicle and most of my around town driving was below say 45 MPH then I would go for a deep gear. On the otherhand if most of my driving was in the say 50-80 MPH range I may want to go with a tall gear. A good tradeoff is a gear in the 3.5-3.75 range. Also something to consider is power band and tire size.
Chevy rear and its axle bearings...axles are the inner races. But they have a repair kit! My 'repair kit' would be the installation of a 9". (done a lot of 'em)
As squirrel said '57-'59 ford car is pretty much a bolt in and wagons/rancheros may even be big bearing housings. I think Granadas are around 58", same as Chevy II and I know I've seen a drum brake 9" under a Mercury Monarch at the junk yard before. 8" rears are pretty stout too and can be found under Mustangs, Granadas and Mavericks. Latter being 2" narrower than the Chevy II rear allowing less back spacing and easing tire changing. Don't forget the Mopar 8 3/4". Not sure but some may be a bolt in as well, A body?
Just the way that you worded it reminded me of a movie I watched on my birthday. Young guy says to an old guy, "They call me nine inch." The old guy says back, "nine inches if what?" But you are absolutely correct, I am eat up. The bad part of it all is that I know it and am not looking for a 9 step program to correct the problem.
My 62 nove II had a 57 pont under it with 4.88 with L60 15 that was just about right for the 327 with a 4 speed.
4.88s behind a Muncie? Hell, that's a 'Santa Clara' gear. We used to race for 2 blocks, sometimes got 6 runoffs before we woke up the Santa Clara cop! Long time ago...
In the eighties, I put together a '64 SS with a Johnson Machine built 350 Mouse Motor and an A1 Powerglide. I kept the 10 bolt and added disc brakes front and rear. It never broke and was street-driven daily. On the Freeway it was like a sprint car. You could accelerate, and brake, without any problems. Zipping in and out of traffic was a breeze. My wife drove into Hollywood from Pasadena and back, week in and week out, to work; and being a Southern girl and born speed demon she drove it harder than I did. I figured if it didn't break, I wasn't going to fix it. I did, however, consider a 9" Ford 'just in case'. Never happened. BUT, that was for a particular kind of mania. It never got jerked around at low speed, no burnouts, and even so the Glide eventually went sour and needed to be replaced. A four speed, on the other hand might shock the system, and breakage could happen in a New York Second. Who knows? Go with a 9" out the gate and, friend, you won't need to sweat the small stuff. I've used them in other applications and they are pretty much bullet-proof. Which is not to say they can't be; because some folks can break an anvil.
You will get 50 different versions on what to run. But 9" Fords use HP, you need to have a different set of wheels or redrill your axles and drums. 12 bolt pretty much a bolt in. Olds/Pont. expensive and same problems as 9" (my favorite by I'm old). I tell anyone who will listen when they ask a question like this or "what came to run on my car" and you get all the Summit and Jegs mechanics answering. LOOK AT WHAT THE NHRA STOCKERS ARE DOING. Bigger isn't always better! Pat
Thanks for all the replies May just see if I can get a locker for my 10 bolt and see if that makes any difference ? Posted using the Full Custom H.A.M.B. App!
Don't Fix it, if it ain't Broke. Ran a 408 cu.in. small block in the last body style El Camino with the factory 78 rear end. Transmission was a built 350 Turbo. Never Broke It.............Jeff
It all depends on how deep your pockets are. In the long run, it may be more expensive to do up a Chevy 10 or 12 bolt. I did a Ford 9" in my '66 Nova, I had it narrowed slightly and the spring perches moved inboard a bit for cheater slick clearance. Think the mods cost me $200 in 1976.
I would not put a stock 10 bolt behind 375 hp with 8-9" slicks at a track. There was another thread here about a guys 35 chevy that broke an axle right at the bearing while racing, and rolled it. I had 67 camaro with a 9 inch out of a bronco, actually it was 3/4" narrower that stock 10 bolt. You would have to remove the spring pads from the bronco, and add you spring perches for the correct spacing.
Going through this right now with my latest OT drag/street car and keep going back and forth on what direction I should go. I spoke to a guy last weekend that has a built 10 bolt who races and drives the hell out of his car on the street. Car has run consistent low 12's for years and the 10 bolt has never given him an ounce of trouble. Granted, it is built with good axles, gears, etc. At this point, I think I'm leaning towards this route.
It might make a difference what stuff you have already, or can get at a reasonable price. I got the 57 wagon housing years ago for free. I added custom aftermarket axles, Chevy brakes, and it has a Strange center, with a Locker, Daytona pinion support, and 1350 yoke. the only old Ford parts inside are the ring and pinion.
That's one of those things, you do it right once and it will last a long time with regular maintenance. With the stock cars, guys with the 12-bolt rears, every now and then someone would either lose an axle or have a bearing seize up and break the axle off at the flange. Anyone with a 9" Ford, those never broke.
My point exactly. Avoid the 'design flaw' in the first place. Look around, there are still 9" rears that Currie hasn't found... I got my first one in '71, out of a '57 station wagon, 3.54 gear, nice condition. $10, cash. Second one was $20, (out of a '58 Ranchero) but it had brand new brakes! LOL The one in my '55 F100 came out of a '60 Ford pickup rear half converted to a trailer...guy said if I'd switch it with my Dana, I was welcome to it! 3.78 gear! Recently got one with a 4.11, out of a '65 Ford F100...60" wide, large flanges (5 on 5-1/2") for my 8-1/2" Torq Thrusts. (for my '54 Ford Coupe...$45 at a scrap yard) Look for old trailers converted from mid-'60s to '70s Ford pickups. Buy the trailer, save the rear.
I've had a bit of experience with cars driven primarily on the street with an occasional trip to the track on street-type tires (not cheater slicks, etc.). Here's what I found to be true: you can't get enough bite to damage a professionally set-up 10-bolt posi with gears in the 3.25 - 3.50 range - especially with a car as light as a Nova - on street tires. I also found that driving a non-overdrive car with gears above 3.5 on the street is not pleasant...especially if there's much freeway driving involved. A very pleasant and affordable combination would be to have a race shop convert your present 10-bolt rear end to a 3.25 to 3.5 positraction using a true posi unit from GM or aftermarket. So...turn your car into a racer if you want, but you'll pay the price in both $$$ and street driving pleasure. My $.02
That GM posi unit will break pretty easy. Better to get a Yukon or Eaton. After market gears, solid pinion spacer, studs for the bearing caps, aluminum housing cover with the cap supports and hardened street axles. The Nova is light enough you are never going to break it.
Uh, I am not a "summit/jegs" mechanic, pretty sure that Lingenfelter wasn't either but he wasn't ashamed to paste their stickers on the sides of a couple of his cars. The chevy rear ( 10 or 12 bolt) built properly will handle a lot of zot. Like I said the cross pins on an open GM rear will not take much abuse. For the cash you are going to lay out to build a GM rear that will hold up, you can snag a junkyard 31 spline 9" ( I guess that would be a summit rear end ) you won't break it with the 327 and still have money to go racin'. Actually I have a confession to make, I like 9" Fords and other drop out chucks because I don't like laying in my back under a car to change gears. I would run an Olds or a Poncho if they were not made of unobtainium. The 8.75 Chrysler you have to watch, a lot of them were lug posis and once the posi is worn it is a throw away.
Hey Beaner, they have a saying at the Fire Department, "it doesn't matter how big your hose is as long as you can put out the fire".
had a 9" ford in my 66 nova and dropping out the 3rd. member makes it simple for gear changes, can't tdo that with a 12 bolt or Dana style.
The 9" Ford has been known for decades as 'The poor mans quick change"for a reason.Damn near bullet proof too.Altho,there are some folks that can tear up an anvil with a feather. Good luck.Have fun.Be safe. Leo
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