Ok So I have a question about rear tires/wheels offsets tire sizes and what not.
I know on 4th gens you can shorten the rear end housing order like a 4.5" or 5" backspace and put a BIG drag radial underneath without mini tubbing and without much cutting...
Can this be done on a 3rd gen?Anyone got big drag radials(325/50/15) or something like that...
Im helping my cousin out with his camaro and ive never looked into a 3rd gen much just trying to get an idea for it..

BTW its an Iroc Z(89 maybe?) and im building a alum head roller cam 383 sbc for it, pretty much gunna be full suspension..
Thanks guys!

 

Typically the most popular big rim for a third gen is a 15 x 10 with 5.5" backspacing.

A 28 x 9 slick will fit with no problems. A 325/50/15 is only 27-3/4" tall and has 11" of tread. It should fit but some inner fender modifications may be required. A 275/60/15 will fit with no problems.

 

3757R P325/50R15 28 X 13.50R15 36 R2 10.0 13.0 11.0 28.0 87
Thats the tire id like to use, the big mickey drag radial.
Do people keep the rear ends stock widths or chop them?This will probably have a Dana 60 and wilwood drag brakes also!

 

I have a 295-65-15 drag radial with out tubing the car I used a holeshot wheels with a 5 and 7/8 backspacing. And that is all that I can get to fit under the car.

 

You don't have to narrow the diff to use bigger tires inside the stock fenders. You just need to use a rim with the proper backspacing to center it in the wheel well.

Why would you want a big, heavy, power robbing Dana 60 under the car? A 12 bolt or 9" is more than enough for a high HP car.

My current tires are 29.5 x 10.5" slicks. The tread is really only 10" wide and the sidewall width of the tire is 13.1". The tire height is almost 2" taller than what you want to use so a wider wider with a taller height needs more inner fender modifications. You want to use a tire that has a sidewall width of 13.5". Personally I don't think they'll fit even with the shorter 28" height without some sort of fender modifications especially to the inner fender front radius and the bump stops.

See this thread for fender modifications
https://www.thirdgen.org/forums/fabr...fications.html

 

The dana 60 is a stronger rear end then the 9 inch, UNTIL you start putting lots of money into a 9 inch.. A Dana isnt that much heavier and the posi's are a little stronger than the 12 bolt. Ive seen problems with the Moser posi's(eaton 33 spline) and ive used numerous 12 bolts so I was thinking of using something a little different.

As far for inner fender mods, I know the bump stops will probably get cut off and im sure the BFH Mod will be used. I didnt know if you must do any fender rolling with adjustable control arms/panhard. So thats why I was asking.
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also I know on the 4th gens people cut the rear ends narrower and run a less offset to give the wheel a nice deep dish instead of a tiny lip like most of those cars have with the 6.5" or 7.5" offsets..

 

Put a third gen diff under a fourth gen. That's an instant 2" per side shortening.

Even I don't need a Dana 60 under my car. It's overkill for most cars. They're better suited for trucks. They're also a pain in the *** to set up.

Dana 60 is about 70 pounds more than a 9". That's a lot of extra weight.

 

I know all 3 rear ends will work simple enough.
Also I wasnt aware the 3rd gen was narrowed..
Also what kinda 540 you got...
my shop has built dozens of 540 inch motors...Got a couple low 9 second 3500 street cars on race gas N/A
I myself like alky, I got a 496 iron head motor single dominator on alky makes about 750 hp, nice mild bracket motor..
But Im building a 540 this winter hopefully just on the other side of 1000hp on alky with 1 dominator!Conventional head too!

 

Dart big M block. Custom built, not any kind of crate engine. See my web site for all the specs.

 

thats cool, with a little more bump stick youd probably be running low 9's easy!

 

"A little more" would mean a Prostock cam. I could run low 9's at sea level. A typical race day here is 5000 feet density altitude. Anywhere I go would be a lower elevation. Well unless I go to Denver. If I wanted to make more HP, I'd need to change my small rectangular port heads for some bigger ones.

If I wanted to go faster, I'd pull the engine from the heavy car and drop it into an Altered. That would easily put me in the low 8's. A full tube chassis car in the 2400 pound range would also help.

 

No not a pro stock cam, but my 496 has a slightly larger cam than what yours is and I have GM iron heads...
P&P your heads and put a 290 something duration high 800 lift cam in and I bet that thing ROCKS even more than it does..

IM sorry im not trying to knock your combo, im sorry if I come off as a jerk...

 

i have 325-50-15 on a 15x10 with 5.5 inches of back spacing.they hang out a little.

 

Too hard on valve springs. Like I said. That's close to a ProStock cam.
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How about the room on the inside?