Was the 8.5 stock? The ford and the 12 are close to the same stength stock but yes the ford can be made to be stronger, another reason they are popular is in the changing of the gears the ford is quicker, the 12 bolt takes away less hp and weighs less(stock), I totally agree with you on the cost to buy a 12 bolt is more expensive to buy, heck I have an open 10 bolt setting in the weeds. It is a bit of work making a rear end fit that was not standard (I just put a 67 chevelle rear in a 79 camaro) To do it again I would have found a 12 bolt that had the mounts in the same position. The 72 -75 nova 8.5 seems to be the ticket for the 1st gen.

http://www.chevyhiperformance.com/te...grade_install/ good artical on it

 

go spend the money and buy a 12 bolt with 350 gears. then turn around and sell the 10bolt or save it

 

I had the same question when I was considering a rearend for my 67.

Consider what you are going to do with the car. Under 400hp, keep the 10 bolt and spend $700 bucks for the rebuild. Between 400hp-600hp go with a 12bolt. Anything more that that seriously look into a Ford 9". Check out this Currie rearends if your going to buy new and money is no object.

http://www.currieenterprises.com/cestore/home.aspx

When I finially made my decision it was:
3.73 Richmond ring and Pinion set
Auburn Posi
Oversized axle barrings and seals
Stock Axles

I'll be installing a 383 stoker motor this winter and don't expect anything over 450hp max so a "non-bullet proff" rearend was not a problem for me. Just remember you can always upgrade later.

 

If your gound to pound on it with a pumped up Rat I'd look at a 12 bolt but if you are running a mouse and mostly street driving a 10 will
do.
Here's a nice 10 bolt posi on ebay!
Just plug & play.

http://cgi.ebay.com/ebaymotors/67-69...QQcmdZViewItem

 

From what I could see in the pics, That is a **** pattern. It's walking off the top of the tooth. Most new gears are set up at .008 backlash, .010-.015 for 8.8 fords, Unless that is the gears origional setup I would not buy it. Used gears usually set up at .010. On a used gearset you can't run anything other than the already established wear pattern or you'll tank the gears. I bet that rear end sings nice and loud going down the freeway, especially with 3.73's in it.

 

absolutely well said!

 

[quote]ORIGINAL: v8chvyguy

From what I could see in the pics, That is a **** pattern. It's walking off the top of the tooth. [quote]couldn't see that at all?

another great statement

 

[quote]ORIGINAL: v8chvyguy

From what I could see in the pics, That is a **** pattern. It's walking off the top of the tooth. [quote]

I couldn't see that at all?

another great statement

 

Actually I think it was third gen 4th gen they didnt start using the 8.5 ubtill 72 but you still need to make sure because they used the 7.5 in those years also. again this artical spells some of it out. http://www.chevyhiperformance.com/te...grade_install/ Do watch on buying a rear assembled with used gears mine is howling so i have to have another gear set put in.