Build Thread: '87 442 . . . Time to turn and stop

[Canon_Mutant]

Though I was supposed to be doing this all winter, with my stupid health quirks I am FINALLY getting fired back up on my build project. Plus doing some more sound system work. Though I love Alpine speakers, I had already gone with JBL out back and in the dash because I think they are just as good and are cheaper but these Alpines have a directional tweeter and 2X the power handling capability of the 5.25 JBLs that are only 45W/per. I was going to go with JBL components and just put the tweeter up in the dash but you would not believe the amount of sound that comes out of these dinky 3.5" JBLs [below] I bought a while back just running off of the head power with below 300Hz blockers on them. I have [2] 100W/per amps to power it all in the trunk because I am anally symmetrical almost to a fault [truthfully it is also a tad easier to wire in some cases] and a single 300W 10" Rockford Fosgate sub in the trunk. As I posted a few posts ago, I sold my Sony head for a RetroSound unit.

Same color but not my 442 door obviously . . . just the Gbodyparts pic.

Speaker p*rn . . .

These mount on the under side of the dash mounts to get them low enough so the tweeters clear the covers.

Going with the 4x10 to 6x9 hanger converters until I get tired of the slight sound loss and cut some 6x9 holes on the deck.

2X of these.

And though I won't be buzzing bumpers with what I listen to, I picked this sub because of its size and shape.

As you all probably know, they face backwards intentionally and the angle on the backside of this looks like it was literally made for the Gbody rear seat along with fitting perfectly in that vertical space too. Though I will screw it down, it fits so well, you really wouldn't have to. Otherwise, for what I listen to, 300W is probably overkill but it should add some nice ka-thump . . .

 

[Canon_Mutant]

As if I need to spend some more money . . .

I know I am going to wish I went 3.42 on this build. I am at 3.73 which is fine for straight line but going 3.42 allows for a slightly better cruise rpm range, should [with all my other changes] help hook up the big block torque a bit better, will allow me to run most auto-x in first, and of course increases the top end speed slightly.

Problem is I am not a rear end expert. I've heard great things about Eaton. And, though perhaps swapping to a completely different rear end design would be best, I do want to just modify my existing 8.5 especially since I already have all the UMI control arms, lowering brackets, Eibach springs, and Bilstein shocks, and even a PURDY aluminum cover for it.

If I wanted to do this while I have it out doing the blast and coat, what all would I need to convert?

Could someone provide a parts list?

And, would I want to go ahead and convert from 28-30 spline axles? I would LOVE to increase the size/strength of my rear yoke. Having all of this torque connected to the rear end with 4 little M6 bolts is a bit disconcerting . . .

Going to make some calls next week but thought I would post here for some thoughts?

 

[Injectedcutty]

Here is the correct part# for the moser 30 spline axles for our cars. I too will be upgrading my 8.5 in the future to these axles, and possibly dropping my gears down from 3.73 to 3.42 since i will be cruising more. Once i find the correct posi diff i will post it. HTH

 

[Injectedcutty]

Here are the other goodies needed, minus the ring and pinion.

Btw, what's the status on them fancy new Saber's?

Scott

 

[Canon_Mutant]

Started a conversation with Mike at QuickPerformance but thanks a bunch for this. I just think that on the one hand I should just drive the damn thing for christ sakes but I also have a feeling that while I have it out and it would be entirely too convenient . . .

. . . what the hell? I was hoping whatever I do would bolt up in the factory differential but, oh well . . . as long as all my UMI stuff will still bolt up?

Sabers are 2 weeks out . . .

 

[Injectedcutty]

Started a conversation with Mike at QuickPerformance but thanks a bunch for this. I just think that on the one hand I should just drive the damn thing for christ sakes but I also have a feeling that while I have it out and it would be entirely too convenient . . .

. . . what the hell? I was hoping whatever I do would bolt up in the factory differential but, oh well . . . as long as all my UMI stuff will still bolt up?

Sabers are 2 weeks out . . .

Might as well rebuild it while its out buddy! Quick performance are good people, I've heard nothing but positive feedback from people who've used them. It was quicker for me to pull up my summit wishlist as I've had those parts saved for when it comes time to do mine.

I've read on here that us guys with the 8.5, can actually use a 8.6" ring and pinion without any clearance issues, and that quick has the stuff for it.

There shouldn't be any issues of using all the new UMI goodies once the rear is re-done. Bolt it back in and go.

 

[olds307 and 403]

Are you doing the rear gear swap yourself? Do you drive at 70 mph or better often? With the 2004R and stock tire height, you will be around 2000 rpm at 60 mph. I found this calculator accurate, if you are running the lock up torque converter. http://tech.oldsgmail.com/ch_axle.php

 

[Canon_Mutant]

Are you doing the rear gear swap yourself? Do you drive at 70 mph or better often? With the 2004R and stock tire height, you will be around 2000 rpm at 60 mph. I found this calculator accurate, if you are running the lock up torque converter. http://tech.oldsgmail.com/ch_axle.php

Yup, that would explain why with the 26.7" 245/60/15s I am running now, my 60-70 cruise range is 1800-2200 with my 3.73. Since I've quoted that in other posts . . . sure am glad I wasn't lying. 🙂

You know, the whole go to 3.42 thing came from that is what UMI is running now in their Monte. Seriously, almost tempted to go up to 3.23 now. Plus my other objective to try and stay in first running [at least most] auto-x runs also would favor 3.23.

3.23 would make 60-75 cruise range 1635-2044. With all the torque my big block makes early on, it would happily do that all day and might well get me above 20mpg in closed loop lean burn mode too.

Since we set it up to go into OD at 45 and lockup at 52, that could cause some problems though? That's down at 1200. But that's easy to control with the shifter . . .

Hmmh . . .

 

[Streetbu]

Do you mean 30 spline axles? You buy them and buy a carrier that accepts them and install. The axle tubes have nothing to do with how many spline axles you have or use. Sorry I don't mean to come off like a jerk, I guess I just don't understand what you're asking.

 

[Injectedcutty]

Hey, Mike's at Quick is really busy apparently. Good problem to have . . .

Do you guys know how you get 30 spline tubes on a 8.5 10 bolt? He has everything else I need but I don't want to go Ford 9".

I am starting from scratch on the rear end learning curve . . .[obviously]

The parts i posted previously are for converting to 30 spline axles with the correct carrier. Just need to pick out a set of gears to your liking, have someone with experience load everything into the 8.5" correctly, and done.