Chevy Nova Forum banner

1 - 7 of 7 Posts

·
Registered
Joined
·
66 Posts
Discussion Starter #1
Our original car had a 307 with PG. Which means we have a 10 bolt rear end with the original factory gear ratio. I can't tell from the factory manuals what the ratio would be, and we haven't had a chance to confirm what the ratio is with the driveshaft down.

We have since moved up to a modified 350 with TH350 combination. We have plenty of hosepower now, but obviously that gear ratio is a problem when taking off.

I see several rear axle suppliers advertising $1500 rear axle set ups ready to go with a posi. Are they worth it, or are these just teaser ads, and aren't worth the money?

We aren't planning on any racing, just an occasional burn out and cruising, so I am looking for opinions on how crazy to get!
 

·
Premium Member
Joined
·
1,536 Posts
The 10 bolts aren't junk. They can withstand some pretty good abuse from what I've read on this site.

If you plan on just cruising and an occassional burnout, I'd say just tear down the 10 bolt, get yourself a posi unit, a new set of gears (after calculating what kind of rpms you'll be pushing at say 30 mph and 60 or 70 mph), and a complete kit (bearings, seals, etc.) for the install. Then spend a day or two assembling.
 

·
Moderator
Joined
·
14,584 Posts
10 bolt rear

The ten bolt rearend you want is the 72 and newer one. It is the 8.5 ring gear. The 10 bolt prior to 72 is an 8.2 unit. The 8.5 is much stronger than the 8.2.
 

·
Registered
Joined
·
436 Posts
The ten bolt rearend you want is the 72 and newer one. It is the 8.5 ring gear. The 10 bolt prior to 72 is an 8.2 unit. The 8.5 is much stronger than the 8.2.
Camaros used the 8.2", Novas either had a 7.5" or 8.5".

All 68-75 Novas came factory with 8.5" rearends, and some 76-79 if ordered custom, and all 68-79's are completely interchangeable without modification. Then all you need is a posi carrier, gear set and bearing kit. You can get the rearend from a junk yard for under $100, a carrier & gear set on ebay for around $200-$300 and new bearing kit complete with everything to rebuild it for $110 from Summit. Total investment about $500 + time to set it up, or a good rearend shop should be able to set it up for under $300 tops. That'll still save you $700-$800 going that route.

Even if you buy all new parts including a good performance carrier, gears, bearings, Moser axles and special tools to set it up yourself, it'll still cost you under $1000, and you can always resell the parts you don't use to recover some of the cost.

The $1500 rearend is probably just rebuilt with used parts and new bearings, possibly new gears, but not likely unless they tell you that. Most will say rebuilt, all parts inspected for wear and replaced as needed, but don't actually tell you whether or not it was needed, so you could just be getting used anyways.

I'm setting mine up now with a posi carrier I got off ebay for $225 with a set of 3.90 gears that I decided not to use since I'll probably see more street time than race. Make sure you get the the S-Spring type Series 3 carrier. I'm going with Richmond 3.42 gears so I can maintain streetability, new cost $180 and bearing kit $110 from Summit. Used gears go all the time on ebay for under $75 if you want to go that route. My total investment so far is under $500, but I now also need new axles ($250) and I'm going to go ahead and get a pinion depth kit ($90) to ensure I set it up properly the first time.
 

·
Premium Member
Joined
·
3,257 Posts
Used gear sets off E Bay can be risky since you never know if they were set up correctly the first time. If they were not set up correctly they may howl even it set up correctly by you since they take a permanent wear pattern the first time they are installed. No amount of adjustment will silence an incorrectly installed used set if they howl.
 

·
Registered
Joined
·
9,967 Posts
jade76 said:
Camaros used the 8.2", Novas either had a 7.5" or 8.5".

All 68-75 Novas came factory with 8.5" rearends, and some 76-79 if ordered custom
I wasn't aware you could get an 8.5" 10-bolt rear end until about 1972. Until that time the 8.2" 10-bolt was standard.
 

·
Registered
Joined
·
436 Posts
Originally Posted by Mike Goble
I wasn't aware you could get an 8.5" 10-bolt rear end until about 1972. Until that time the 8.2" 10-bolt was standard.
Perhaps I'm the one that has the bad info on that one. You're right, checked my source and it's 72-79. 68-79 on other parts.

My bad!!! :confused: Just shut me up!!! :awkward:
 
1 - 7 of 7 Posts
Top