Chevy Nova Forum banner

21 - 40 of 45 Posts

·
Registered
Joined
·
19 Posts
Discussion Starter #21
If the rearend guy is telling you that you are ( right on the cusp from transition from 8.2" to 8.5" ) I would not use him, he doesn't know that the 8.5" came out in the 1971 Camaro, and in 1972 Novas, and other GM cars, it was GM's replacment for the 12 bolt, If it is the orginial rearend in his 1974 it will be an 8.5". I would go with the Eaton Posi. Look through this and you might be able to get the numbers off the axle tube and know what gears it came with, no guarantee that they haven't been changed though, also it shows you how to tell the difference between the 8.2" and 8.5"

.
Dude has legit reviews on Google. Seemed very knowledgeable, at least for two knuckleheads like us. Seems he does all types of rear ends so not worried if he doesn't know the GM years by heart. He said he's been doing it 12 years and sounds like a younger guy. We sprung a lot of info on him over the phone out of the blue so could always be a little miscommunication. I'm sure we'll get it sorted.


Also why the Eaton Posi? Just wondering. He said if we have the 8.5" (I'm thinking we do but will verify with my uncle when he gets off work) then he could go Eaton, AAM, or Motive helical gears, if that's what we want. My Uncle just wants the one that is less maintenance that will get rid of the 1 wheel peel. Not that he is going to be doing much burnouts but nevertheless he wants it lol.
 

·
Registered
Joined
·
19 Posts
Discussion Starter #22
So you are in San Antonio, Tx. ? I have family south of there, and a friend there, I will see if they know of a rearend place that they would recomend if you want.
Yes actually was born and raised in a little town called Leming, near Pleasanton in Poteet. I live in SA now and my uncle still lives out there.

This is the place we were looking at going with. Has good reviews. I'm sure he could do what we are wanting. He said if we have the 8.5" he could do Eateon, AAM, or Motive Helical gears, if that's what we were wanting.

 

·
Registered
Joined
·
235 Posts
Ok, thanks. We will check it out. What does it mean that intake wasn't bolted on? I think the main reason my uncle liked it was for the looks. He liked the eye candy and custom intake. I don't know very much about engines, nor does my uncle.

We have been looking at the Blueprint engines on their site and from summit racing. How is something like this?

not that either says externally balanced...
 

·
Registered
Joined
·
19 Posts
Discussion Starter #24
not that either says externally balanced...
Is externally balanced good or bad? Excuse my ignorance... All the GM performance ones show externally balanced as well as the BluePrint ones. Probably a little over budget, he wants to be more around 4K to 5K max out the door. The one he wanted from ebay was like 5.3K shipped, he offered the guy 5K for it because he really wanted it but that wasn't enough to buy it. The 350 he already has in there is fine though so no rush. He said it leaks a lot of oil and stuff but might as well just send it while he's got it in my opinion lol.
 

·
Registered
Joined
·
235 Posts
Ok, thanks. We will check it out. What does it mean that intake wasn't bolted on? I think the main reason my uncle liked it was for the looks. He liked the eye candy and custom intake. I don't know very much about engines, nor does my uncle.

We have been looking at the Blueprint engines on their site and from summit racing. How is something like this?

 

·
Registered
Joined
·
235 Posts
Is externally balanced good or bad? Excuse my ignorance... All the GM performance ones show externally balanced as well as the BluePrint ones. Probably a little over budget, he wants to be more around 4K to 5K max out the door. The one he wanted from ebay was like 5.3K shipped, he offered the guy 5K for it because he really wanted it but that wasn't enough to buy it. The 350 he already has in there is fine though so no rush. He said it leaks a lot of oil and stuff but might as well just send it while he's got it in my opinion lol.
externally balanced bad internal good
 

·
Registered
Joined
·
19 Posts
Discussion Starter #31
just so ya know my heads,valve-train, intake and carb alone cost more than that entire motor should
Sometimes ignorance is bliss! The less you know the better off haha. I mean as far as wanting "the best" of everything. Not Nova related but I recently bought my first truck (also my first Chevrolet). 2020 6.2L 10-Speed RST Z71 4WD, All Star edition, Safety Package, Leather package, Continence I&II package, G80 rear end, etc. Funny thing is I do not tow or off-road at all, so I definitely understands why my uncle wants a "high end" drive-train, engine, etc even though he doesn't "need" it. When you want it you want it lol.
 

·
Registered
Joined
·
472 Posts
For use below a constant 6500+rpm like circle track, anyhting less than that there is nothng wrong with external balance...we built and raced external balance 383 and 406 SBC's on street/strip and drags for 20 years before "internal balance" became the new hot buzzwords and never had any extreme problems with it. 454 and 502's have been that way from the factory fo 50 years....guys have built a lot of 700 Hp 7000 rpm 454's external balanced without problems for a long, long time.

On the GM Perf SP383, what I don't like is they give you a forged crank and 4-bolt block, a pretty good head, and then stick crummy hypereutectic pistons in it....it isn't an "all forged assembly"....all forged means forged pistons too.

Unless someone blew up the rear in that '74 Nova and back-fit a '68-71 8.2", it is going to be an 8.5" from the factory....no other axle was used in 1974 Nova's. At that time, the 8.2" hadn't even been manufactured for 2 years time, it was gone..

As far as weight difference between 8.5" 10-bolt and a 12-bolt, it is about 15 lbs is all....nearly everything is the same except about 1/8" in axle shaft diameter and 3/8" in ring gear diameter....everything else is the same...bearings, seals, brakes, tubes, yoke, backing plates, even the center casting is so similar in size as to make no real difference.
 

·
Registered
Joined
·
19 Posts
Discussion Starter #33
Sweet, looks like an 8.5" to me!

Now the only question is if we go with the TrueTrac or something similar? From the limited understanding I have we want to go with helical-gear LSD.
409524
 

·
Registered
Joined
·
472 Posts
Yeah, that is 8.5.. Helical is smoother engagement in and out of turns, doesn't require a friction modifier added to the fluid like a clutch diff does, and doesn't wear and need rebuilding like clutch plate diffs do...although if properly cared for with fluid changes the clutch plate diffs will go 20 years between rebuilds.
Clutch plate diffs can also sometimes be an issue in wet or slippery conditions with a tendency to drive the car straight when trying to turn.
 

·
Registered
Joined
·
235 Posts
Sweet, looks like an 8.5" to me!

Now the only question is if we go with the TrueTrac or something similar? From the limited understanding I have we want to go with helical-gear LSD.
View attachment 409524
the rust would be my main focus...it's unacceptable rotten brake lines ...exhaust ...you got more project than you bargained for...it's not structurally sound or safe...looked nice on top...good luck
 

·
Registered
Joined
·
3,812 Posts
Yes actually was born and raised in a little town called Leming, near Pleasanton in Poteet. I live in SA now and my uncle still lives out there.

This is the place we were looking at going with. Has good reviews. I'm sure he could do what we are wanting. He said if we have the 8.5" he could do Eateon, AAM, or Motive Helical gears, if that's what we were wanting.


Cool, my cousins live in Devine, and her husband is from Dilly it's off of I-35. He used to be a welder, welding around the oil fields
 

·
Registered
Joined
·
19 Posts
Discussion Starter #37
the rust would be my main focus...it's unacceptable rotten brake lines ...exhaust ...you got more project than you bargained for...it's not structurally sound or safe...looked nice on top...good luck
Hopefully just a little surface rust. Just a cruiser, not going to be drag racing the thing. I'll bring it up to my uncle but I think we are just going to send it lol. He's had the car over 20 years and has been using it like this. Garage kept and we don't get any snow. Does have a couple of bubbles in the body too which he plans to get cut out. But we aren't doing a frame off restore or anything. Just changing out some parts and going to call it good enough lol.
 

·
Registered
Joined
·
19 Posts
Discussion Starter #38
@Redrider66SS @bracketchev70 @Ericnova @nova 71-436 @Nova Thug @firebird69racer

So supposedly the axles are shot. I say supposedly because I know nothing about them and we didn't care to ask why/how they were bad. I told my Uncle well that is good news, that means you get to upgrade to 30 spline!

6226636381.jpg
6226636451.jpg
We are going with a Nitro LSD (Posi), based on the recommendation from the axle guy. Also decided on 3.42 gears coming from 2.73

I assume it is this one.
.

A little bit of eye candy as far as the cover goes. We are also getting the diff media blasted and painted (opted to not add powder coat as the painting is free and powder coat adds $150)
NPCOVER-GM8.5-FSJK_1080x.jpg

Also my uncle bought a gas tank, fuel sending unit, rear leaf springs, front and rear shocks, and he even got under it and ground off a little bit of the surface rust and oxidation. Needs some new tail pies lol.

0923201846.jpg

What do you guys and/or gals think?
 

·
Registered
Joined
·
472 Posts
In my opinion the Trac-Rite GT helical gear diff from American Axle is a better piece, based off the fact they are making it for GM production, so they have better quality control standards in the manufacturing process. It's also priced a lot better, nearly $130 less.

Yeah, those stock axles are shot, wear and pitting in the section that rides on the axle bearing rollers(that dull section between the two shiny sections).

If you need an axle upgrade on a budget, the axle shafts for a 12-bolt '67-69 Camaro/'68'72 Nova will work for 30 spline 10-bolt upgrade if you cut 1/16" off the face of the c-clip button...12 bolt has a 5/16" thick button, 10-bolt is only 1/4" but otherwise the axles are the same length/housing width and same wheel bearing, so trimming the button in a lathe is super easy way to make a common lower cost replacement axle fit instead of costly custom axles.
 

·
Registered
Joined
·
19 Posts
Discussion Starter #40 (Edited)
In my opinion the Trac-Rite GT helical gear diff from American Axle is a better piece, based off the fact they are making it for GM production, so they have better quality control standards in the manufacturing process. It's also priced a lot better, nearly $130 less.

Yeah, those stock axles are shot, wear and pitting in the section that rides on the axle bearing rollers(that dull section between the two shiny sections).

If you need an axle upgrade on a budget, the axle shafts for a 12-bolt '67-69 Camaro/'68'72 Nova will work for 30 spline 10-bolt upgrade if you cut 1/16" off the face of the c-clip button...12 bolt has a 5/16" thick button, 10-bolt is only 1/4" but otherwise the axles are the same length/housing width and same wheel bearing, so trimming the button in a lathe is super easy way to make a common lower cost replacement axle fit instead of costly custom axles.
Well we are paying $525 for the Nitro. Supposedly we aren't paying any markup on the parts. $131 each for new axle shafts. We are just going to go with what the diff guy recommends. No offense as I am sure you are right but since we don't know any better my uncle would prefer to just go with what the guy doing the work suggests. I believe he said the reasons he likes them is because they engage at lower torque...I'm sure he explained why but a lot of what he said went over my head. I made the mistake of asking what an HD master install kit was and got a history lesson that included a lot of verbiage I was unfamiliar with. Something about pre 1999 diffs.

We are going to be about 2.2K out the door including taxes and labor. A little more than we wanted to spend but no biggie, still better than 4K my uncle was looking at spending on a brand new Mosier unit that was overkill. We even get pics of parts being installed in the diff as part of the deal. Can't wait until my uncle gets the car running again. We used to cruise around when I was a teenager about 15 or 20 years ago. Car has been parked for 4 years in his garage due to issues with a locked up drum. Not sure exactly what the issue was I'm sure if we throw enough parts at it, the issue will be resolved lol.
 
21 - 40 of 45 Posts
Top