[i82much]

ah ... so the appearance is why people go with the 12 bolt instead of a 9 inch or 60 ...

[Gach]

Or maybe it’s the stigma of Ford 9”. Just suggesting.

[b-man]

Originally Posted by i82much

ah ... so the appearance is why people go with the 12 bolt instead of a 9 inch or 60 ...

Sometimes perhaps.

Some people put the 9” in their cars just for bragging rights and just to say they have one, whether they need the upgraded strength (there are many versions both weak and strong) or just like to run the same style rear as many full-on race cars.

I can remember calling up the H-O Racing tech line back in the early ‘90s where Ken Crocie would answer technical questions for his customers. I was telling him about my car and mentioned it had a 9” and he said he didn’t like them and preferred the 12-bolt. If he did tell me the reason I’ve forgotten it, but anyway everyone has their preferences.

Both myself and my friend who I traded one of my cars to for my first Pontiac (which was a 1964 GTO I later learned was a clone) were really into drag racing and having a Ford 9” we thought was the greatest thing in the world. The GTO when I got it in 1989 had a narrowed Currie 9” with a 31-spline Traction Lock and 3.25 gears, a Doug Nash 5-speed behind a ‘69 RAIII 400. All top-shelf stuff for the time.

After a few years I started bracket racing the GTO running a 455 and TH400, it wasn’t long before the clutches inside the Traction Lock were worn to the point where where it wouldn’t burn both tires anymore. I pulled the pumpkin and paid someone to install a Detroit Locker and 3.89 gears. After that I never messed with it, racing it for about another 9 years before finally selling the car.

The 9” fit the theme and purpose of the car and at the time it was a better rear end than a GM 12-bolt but times have changed and now the aftermarket complete new rear ends afford you many more choices. Back then everything was built off of junkyard housings and center sections for the most part, not brand new upgraded components like you can buy today.

[Jay S]

A moser 12 bolt would be the way to go if you want to throw money at it and keep it looking stock. OEM 12 bolts are generally too pricey, by the time you make upgrades to a 1200 open rear end with 2.73s your most of the way to the cost of the Moser, and the Moser is quite a bit stronger.

If you have a N case 8.2 I would get a TA cover and run it and not replace it until something breaks, in the 12s with drag radials, that might be never. But it could be the first pass too, that is drag racing..LOL

The 3.36s seem to be the toughest gear set in an 8.2, a little stronger than 3.55s. Also versus OEM gears, the aftermarket gears also do not have some of the tapers on the pinion machining and are a little stronger. See the photo..

The offset of the 9” rear end is pretty noticeable under an A body. If your going after a OEM type look, it does not fit that. We fabricated had a 9” in a A body before all the kits were available. We did an 8.75 Mopar in an A body also. The 9” with upgrades for power get’s pricey pretty quickly, nodular case with the bigger front bearing support are pretty important upgrades.

For the money, it is hard to beat buying a 8.5, then depending on how quick it is do other upgrades. I bought a 8.5 a few weeks ago from a 72 Cutlass for $350. There was a salvage years that had several 8.5s from 72 Chevelle’s and Buicks, he wanted $350 also. I have seen some asking $500. There were several million of those 8.5s made in 71 to 72, you just have know where to look for them, they put them in every 2 and 4 door combo of A body there was later end of 72. They cost a fraction of the price of a 12 bolt, parts are cheap too.

I have broke quite a few 9” rear ends. I split one grey case open and broke the back pinion support off with a 300 6 cylinder. Split the carrier in 2 on another. I have 2 friends that have broke pinion shafts. JMHO. The Ford 9” are the most expensive rear end to build properly. They run pretty hot compared to other rearends, the worst part of the 3% loss in efficiency shows up in the form of heat.

[242177P]

For a RA II, I'm leaning towards the 8.5" - purely because aesthetics. Take a grinder to one and most folks won't know it isn't an 8.2, "whoa, it still has a 10 bolt". Sneaky. Assuming Ol' Pinion head has one on his racks, he could be a one-stop shop for you. Road trip?

12 bolt is my second choice. Period correct upgrade. Still GM, nobody is going to hold their nose. Perfect if you're wanting to impress the folks who are impressed by the number of cover bolts. The 9" just screams "I've been modified", and the bread and butter parts aren't bulletproof.

[Verdoro 68]

Originally Posted by Jay S

If you have a N case 8.2 I would get a TA cover and run it and not replace it until something breaks, in the 12s with drag radials, that might be never. But it could be the first pass too, that is drag racing..LOL

I have a '69 XH code 3.55 4-pinion posi with a nodular case right now that's not original to the car. It was rebuilt about 10 years ago. The conundum is it's a relatively valuable rear for someone restoring their car. Would a $200 TA cover really add that much strength to it? It would be a shame to blow it up when I could sell it and recoup some of the cost of a more stout rear end.

Originally Posted by Jay S

For the money, it is hard to beat buying a 8.5, then depending on how quick it is do other upgrades. I bought a 8.5 a few weeks ago from a 72 Cutlass for $350. There was a salvage years that had several 8.5s from 72 Chevelle’s and Buicks, he wanted $350 also. I have seen some asking $500.

If I could find a core for that price, the decision might be easier. I was thinking they'd be easier to find around here, but maybe I'm not looking in the right places.

Agree on a 9" screaming "modified: which is why I was leaning towards the 12 bolt. "Keep your GM car all GM"