Which of these rearends?

[Matt300ZXT]

I'm looking for one to put in my 54 and had some local guys offer some up. One guy has one from an 87 full size conversion van that's an 8.5" (one guy on the local forum said that'd be a good one), he also has a 76 Camaro he's parting out still with front brakes, so I could get front AND rear brakes at the same time out of that car. Also another guy has a 74 leaf suspension Nova rearend for $75. Or should I hold out for an S10 4x4?

Ideally, I want a rear end that'll allow me to run something bigger than an 8" wheel. I'm really checking into those Summit Racing wheels that look like the Torq Thrusts, an 18/20 setup. The 18s are 8.5" and the 20s I'd want 9.5".

[bobinbc]

The Nova and the S10 4x4 are both 60" wide but the Nova is a 8.5 which is stronger. The Camaro is also 8.5 but slightly wider and the van one is a bigger bolt pattern 5x5 different from the rest. If you want to put real wide wheels 10"-11" or 9.5" with a deep dish(big lip) I'd look for a 2wd S10 54.5" wide. It'll hold up fine behind a mild V8 on street tires.

[Matt300ZXT]

Cool, thanks.

[a5Ben]

That S10 2wd rear end will be so narrow that you will have to tub the bed. That might not be a problem for you but it was for me so I went with a 61" wide 70's Camaro rear end.

Ben

[bobinbc]

Yes, you'd definitely be tubbin it with the narrow rear. thanks for pointing that out, here's a pic of how I did mine, lot's of other nicer ones here on the board....

[Matt300ZXT]

Well I had a guy offer to give me a 78-88 Gbody rear end but it's only 58" and would have to cut the coil spring perches off and weld on leaf spring perches...I think I'll just go with that 74 Nova rearend for $75 the guy offered up on the local car forums.

[blackdiesel]

You will probley have to move spring perches ether way you go, and will have to tub it to run 9.5" rims.

[raycow]

Stay away from the van rear. It's wider than the pickup rear and you will need really weird backspacing on the wheels to clear the fenders. Stock rear end width is about 62" and you will probably want something narrower than that to keep the wheels reasonable. Check what BS is available on the wheels you are considering before you make any commitments on the rear.

Ray

[Matt300ZXT]

Ok so I'm trying to do some measuring and figure this out on my own. I measured from a lip to a lip on the bed of my 54 (no fenders on it right now), which is about 1/2" difference from the actual outer sides of the bed, and it measured right at 51.25" give or take a 1/4". So we'll say a tad over 50" from one outer bed side to the other. If I run the less wide G-body rear end which is 58" instead of the 60.25" Nova unit, I can run wider wheels, assuming the wheel has more negative offset, pushing the bulk of the width of the wheel into the fender and away from the side of the bed, which gives more of the "deep dish" look.

So if my crappy calculations are correct, if bedside to bedside is roughly 50", and the G-body axle width is 58", technically I could run a wide a wheel as will fit in the fender, in relation to fender rubbing, as long as the wheel has about 3.5" of backspacing (to keep it away from the side of the bed)? However, if I run the Nova rearend which pokes out to nearly 61", I'd have 5" on each side meaning I would have to get a wheel with about 4.5" of backspacing to keep it away from rubbing on the sides of the bed?

Pardon the crappy Paintbrush drawing, but I'm using this to kinda help me figure out wheel mathematics. The 50" bed width and the 58" axle width, divided by 2 is where I'm getting the 4" of space between the wheel mount surface, and the outer sides of the bed, giving me the 3.5" or so of backspacing I'd need at max to give a little bit of clearance and to prevent rubbing.

Back when I was working on my 280Z and trying to find wheels, I used to know all this wheel math and was very good at it, but alas, that's been years ago and I forgot it all, so I'm having to re-learn it all.

Again, this is all theoretical in my head right now and may not work in the real world. I just want to know if my math and thinking is on the right path. Getting exact dead on measurements comes when I go to pick up whichever rear end I decide on, I just want to know if the way I'm using these measurments is correct.

[T Hilde]

Even if you use the reverse offset wheels you are going to be tight. If the rear is 58 inches mounting surface to mounting surface, the brake take roughly 3 inches a side, now you are down to 52 inches, that leaves you 1 inch on each side for the ballooning of the tire. Sounds like a rub to me.
60-6=54-50=4/2=2 inches clearance. The Nova wins by the numbers. Also, how much effort to tub the thing?

My 2 cents

[Matt300ZXT]

What do you mean the brakes take 6 inches total? I don't see what you're talking about right there.

[raycow]

T Hilde is probably right in saying there is approximately 3" per side between the WMS and the inboard side of the brake backing plate. However, I don't understand what is the relevance of that to the wheel/tire clearance calculations.

Ray

[Matt300ZXT]

That's what I was thinking...but even if I did use that G-body axle, finding wheels with 3.5-3.75" of backspacing is pretty hard, unless I want to use a narrow wheel anyways (like I could use with any axle, even the stocker) or pay $400 plus per wheel. Or I could go with Diamond Racing wheels, as I like their stuff, but if I'm going 5 lug, I'm not using a wheel like that, I want to use something HOT and custom looking. Perhaps the G-body axle is ruled out due to wheel selection.

[T Hilde]

Your brake drum is approx 3 inches deep, 2 of them makes it 6 inches. The wheel even on a negative offset would be about the same as the drum, so the backside of the wheel (bead area) would be flush with the backing plate.

[raycow]

Ok, I think I am finally starting to get it. If you don't want to tub the bed you will have to find out what BS you can get on the wheels you like and then select the rear end width to put the wheels where they need to be.

However, I still don't think the backing plate location matters, because there is no way it is going to interfere with anything

Ray

[Tchia65]

Backing plate location will matter if this truck is going to be in the weeds, need more than 1" to fit a brake hose between the rear and the bed. Otherwise as long as all the rears are being measured wheel mounting surface to wheel mounting surface than backing plate location doesn't matter. I have 2 15x10 chrome Rally's with a 4" BS that I can't use on my 58, I went with a explorer diff and need 6" BS.

[bobinbc]

According to the wheel/tire calculator; 9.5 wheel, 4.5 backspace, 245 tire- 9.65" wide, 60" wide rear S10 4x4 or Nova = nearly 1" clearance on the inside and about 0.5" on the lip. I used 72" as a guess for fender lip to fender lip.

tire calculator link

[Matt300ZXT]

I'll kinda mount one of the fenders tomorrow and get a measurement of it at it's narrowest point where the tire would possibly come into contact with it and get an accurate number...then I can really start narrowing down what wheel choices each axle would give me.

[WIDESIDE72]

I am putting doing an S10 frame swap under a 55 1st series and will be swapping S10 4x4 rear axle under it, mainly due to the fact that it was cheap, and I don;t plan to hot rod it too much. (The truck will have a stock LT1/ 4l60E.) Does anyone know off hand what back spacing I will need? I am thinking about running stock Rally weels, 15 x 7 front. Corvetee 15 x 8 rear. I know I can wait til I get to the mock up stage, but I always like to know what I need in case I find a "deal", rather than waiting til I need it and paying more than I have to. I call it "prebuilding". HAHA