I'm considering doing the 4th generation rear end swap like was discussed in an earlier post I made. For a while I was hesitant about this because of the 3 1/2" wider width of the 4th vs. the 3rd gen rear end, but now I'm wondering if that's really that big of a deal. If you're running IROC 16" rear wheels (which have more backspacing then the front ones) with the 4th gen rear I figure the end result would be the wheels would only stick out an extra 1" or so more than with the 3rd gen rear. Weren't the rear wheels on our cars tucked in pretty good to begin with? Would 245/50-16 tires still clear the rear quarter panel lips with the car lowered and inch or two?

Plan B would be to use 4th gen wheels (that have more offset) to bring the rear track back to stock. The problem with this is you would possibly need to add spacers to the front hubs to move the front 4th gen wheels out so the insides of the tires don't rub anything. Or you could use aftermarket wheels with the rear ones using the 4th gen offset and the front ones using the 3rd gen offset.

Does anyone have experience with this swap and could post pictures from the rear of a car what it looks like to go from 3rd to 4th gen rear end with stock width wheels/tires and stock or slightly lower ride height? The Youtube videos and pictures I've seen on this swap never show what the car looks like afterwards from the rear or show how close the outside of the tires end up being to the sheetmetal.

Thanks for any info on this.

 

Easiest way to estimate it would be to take the wheel and tire that you want and put it on your current rear end. then measure from the edge of the tire 1.75" and see where you land.

 

Personally swapping a 4th gen rear end is a huge waste of time. You're not gaining anything. Besides the different width it's the exact same rear end as the 3rd gen. If you're thinking disc brakes just buy a disc brake kit and it on your current rear end

 

I was looking at that you not only gain disc brakes but also 28 spline axles, and better gear ratio and a torsen rear diff if you manage to find the right one. To buy all that and install it in the rear end I have would be very expensive and time consuming. Salvage yards around where I live charge $200-250 for 4th gen rear axle assemblies, and there's still a few availbale.

 

I was looking at it the other way around since I don't have the 16" wheels I want to use yet. I was going to let the rear end I use determine the offset of the wheels I buy. My preference would be to use IROC Z wheels: if I stuck with the rear end I have and went to the (big) expense and trouble of changing the internals I was going to use front (0) offset IROC wheels in back to move the rear wheels out a tad (it's actually not very much). I like the look of the IROC Camaro race cars that had their rear tires pushed out as far as they could go and still be lowered for racing, as opposed to the stock IROC Z set-up that had the wheels tucked into the rear quarter panels quite a bit.

The idea of pushing the wheels out as far to the outside of the car body as possible didn't really catch on until the 1990's for some reason. Now all new cars are that way. New Mustangs have their rear wheels pushed out so far that they look ridiculous from the back.