9 bolt VS 10 bolt
 

From what I've been able to find, neither is really more special than the other if they're both made by GM. I need to pick up a new rear, and my inability to sell my car is making me want to change it to something decent so I can swap a 350 in it at some point in the middle of summer.

I also need to do my suspension if I'm going to keep it, and since I'm such a lazy bitch, I'd like to get the rear, struts, shocks, springs, and LCAs all done together. I'd rather be wrenching for one weekend than 3 or 4 of them. I'm going to make a suspension post as well.

12 bolt.

What is your budget?

Correct, neither the 9 bolt or 10 bolt will hold up to extended abuse. FWIU, the 9 bolt has very limited gear ratios aval.

A couple hundred.

Got one for sale under $600?

I've seen the combo with 2.73, 2.77, 3.77, and some other one. 2.73 is what I've got now, and I'll probably stick with it for the meantime since it's still mainly used as a cruiser.

To me, $600 is an awkward number. Too much to throw into a 10 bolt or 9 bolt but too little to buy yourself a decent rear. In your case (since yours is broken) I would just fix what it needs and put the rest of the cash elsewhere.

Now you see my dilemma. All the 12 bolts I've seen have been upwards of $1,000.

A 9 bolt is supposedly a bit better than a 10 bolt, but with parts harder to find it's not worth swapping one in. I would just do a basic rebuild on the stock rear and call it a day.

- Justin

on that will actually bolt in the car is more like 2k.

Just use an open rear, it kept my little 10 bolt alive for a good long time behind my motor:mrgreen:
________
Amateur tube videos

Probably going to be my only real option. I doubt the 305 will grind the rear away, but I'll probably start being a bit wary of it when the 350 goes in.

The 10 bolt has a 7.5" ring gear (for your year IIRC) where as the 9 bolt has a 7.75" ring gear, both are puny. My 10 bolt has a 9.75" ring gear but I wont get into that.

Buying any quality car part costs a lot of money, a quality used 12 bolt will always be upwards of $1000 like you said, or over 2 new, same with a 9", etc. I would advise to save up some money and put some quality pieces under the car so that when you build a healthy engine the rest of the car can already handle it. It will save you money in the long run, instead of fixing broken stuff (rear, trans, etc) repeatedly.

Good call on the suspension stuff, but just know that doing more things to make the car hook will inevitably end your rears life faster.

All 3rd/4th gen 10 bolts are 7.5" (or 7.625").

- Justin

not EVERY 10 bolt in a third gen is that small

Yea see I wasn't sure if third gens were 7.5 and 4th were 7.625 or what the difference was...

All i know is Josh is right because my third gen definitely has a 10 bolt with a 9.75" ring gear...and I know there were a very few dana 44s just like the one in your car Justin, that thing is a 10-bolt too, correct?

All FACTORY 3rd/4th gen 10 bolts are 7.5" (or 7.625").

The Dana 44 (8.75" ring gear) was only in the 3rd gen Firehawks. It was available as an over-the-counter upgrade from SLP, GMPP, or both (can't remember off the top of my head).

Is that better guys? :D

- Justin

your knowledge is the bestest. :bow:

what the hell kind of ten bolt has a 9.75" ring gear?!?!?! I'm gonna guess that it's not made by GM.

9.75" is a Dana 60, but that's got 12 bolts.

Guess again.

What, is that an incorrect statement about the 60 or do you know what rear it is and that's not right?

60 has 10 cover bolts

I thought they were talking about ring gear bolts.

Yeah, but it has 12 ring gear bolts. I was always under the assumption that the number of ring gear bolts was what determined how many "bolts" a rear was, not the cover. Guess I was mistaken...

dana...GM...does it really matter?

Does GM even make the factory 10 bolt or is it subbed to someone else?

and for the record, i always assumed cover bolts were what we were talking about as a 12 bolt has 12 and a 10 bolt has 10 so I always just kinda put 2 and 2 together...not that it matters but now you have got me curious, does a 12 bolt have 12 ring gear bolts, too?

Dan:

You and Josh are right. I don't know why I thought it was ring gear bolts but that appears to be false.

The "9 bolt" has 10 ring gear bolts, and the "14 bolt" truck axle has 12 ring gear bolts.

The only exception that I seemed to find was one of the GM drop out center section "10 bolts" that has 12 ring gear bolts.

And no, this stuff doesn't really seem to matter but I like to keep my facts straight.