help with 12 bolt info

[low69chevy]

Not sure if this is the right section but figured I would post here since alot of you'll run different types of back spacing on your race wheel. I want to order some Moser axles for my 12 bolt figure I'm going to build it and see how long it last with the turbo setup I have planned for it. My question is I'm going to be running 20x12 racelines with 4" b.s. on the street and 15x12 bogarts with 4"b.s. at the strip I just don' know what size axles I need to order what length.
Here's a pik of my truck with the wheels so you can see how much they stick out



This is a pik of a member from a local forum I asked him and he said he nnarrowed it 4.5 inches each side but to me it looks like the wheel is sitting to far inside but not sure his are 17x12 w/4in b.s.

[cableguy0]

Axle length isn't your issue. Your backspacing is wrong on the wheels. Your axle length is dictated by the length of the rear. If you current have a stock width rear you need to order axles for the stock rear.

[low69chevy]

Sorry for the first post I know I need to narrow down my differential but need to know how much the reason I went 4"b.s is cause I wanted the big lip here's a pik of my daily driver my hd and my ss clone and you can probably see that I like the way the deep dish looks on my trucks and thanks for the response

[slowtruck]

I think you are just going to have to jump under the truck with a measuring tape and figure out how far you need it to be to get the look you want. Just remember you need clearance for the wheel to tuck a little when you hit bumps so it doesn't rub.


The other guys truck looks like he could have gotten away with only 2.5" and brought the wheels out a bit.

[low69chevy]

Originally Posted by slowtruck

I think you are just going to have to jump under the truck with a measuring tape and figure out how far you need it to be to get the look you want. Just remember you need clearance for the wheel to tuck a little when you hit bumps so it doesn't rub.


The other guys truck looks like he could have gotten away with only 2.5" and brought the wheels out a bit.

Yeah I know that would be the best bet but the truck is back in Texas and I'm working in Kentucky right now so it's a 20 hr drive I'm trying to get all my parts ordered so when I go in December hopefully I'll have something to work on to stay busy during the holidays.

[Captainfab]

You have to be careful going by how much someone else narrowed their differential. The early '70 and earlier 12 bolts are 62" wide. The late '70 and up are 63.5".

I know this doesn't help you but the correct way to determine the width/length of a differential is to start with your tires and wheels. Place them the distance apart they need to be and measure wheel flange to wheel flange.

[low69chevy]

I called one of the local shops back at home that does custom work on chassis roll cages etc. he said to narrow it anywhere from 3 1/2 to 4" each side does that sound about right? He said 3 1/2 if I wanted it real close to the bed or 4 if I wanted the wheel a little bit more inside so if i want to drop it more it won't hit the bed

[Captainfab]

There's a 50/50 chance of the differential being the correct length for you if you do not obtain the necessary measurements I described above. Is that guy willing to rework the differential for free and buy you new axles if it isn't correct for your truck and your wheels.

[low69chevy]

Like title says need help on turbo info I'm working on my 69 c10 going to put a 370 with holley hi ram intake 102mm, comp roller rockers, p@p 243 heads,morel lifters,etc. Trans is going to be a built 400 w/trans brake, stall etc. As for the rear end Iit will be the stock 12 bolt with a good posi and narrowed about 4in. each side w/moser axles and moser Gridle cover etc. What recommendations would you give me that would help already have the up and forward headers and a new 50mm tial bov just need the wastegate, turbo, intercooler. Plans are to build a reliable truck that I can drive to the car shows and track on the street it will be on some 20x12 racelines in the rear w 4"b.s and 15x12 bogarts at the track

Was looking at this turbo would this be good enough for my build kind of new to the turbo scene and have seen alot of good builds on here so figured I would ask these are the specs I believe the one I'm looking at is a 1.00ar any help is appreciated


APT Built In-house S480 Turbohargerdum

Starting from a base Borg Warner S400 we have fitted this with a 80mm extended tip billet high flow compressor wheeldum

Compressor cover fresh polish Compact S410 Compressor cover (small vband out)

Wheel assembly balanced. severe duty bearings + 360 thrustdum

Compressor wheel - 80mm inducer / 113mm exducer / 117.55 Exended tipdum
Turbine wheel - 77.5mm/87mmdum
Compressor inlet - 5" hose Ported Shrouddum
Compressor outlet - 2.5" v-banddum
Turbine Inlet - Divided T4 .90 A/R 1.00 A/R 1.10 A/R 1.25 A/R Must Specifydum
Turbne outlet for 4" v-banddum

capable of supporting 1175hp+dum