Kozz167

I am a left right driver more than the strip (though I do love the strip, so I found a 99 IRS for $450 with new half axles, but its the 28 spline. I know My handling will be alot better, but is it worth it with only the 28 spline or should I hold out and fined a 01-04 IRS with the 31 sline to handle my new engine (5.8L) and the posible power she could or will have?

.boB

I'm running close to 600hp through a 28 spline IRS diff. Parts are 4 years old, and no problems. But, my car is 1,000# lighter than yours (give or take). I run it hard on the road course pretty often.

As long as you're spending your time on the road course or cone dodging, I don't think you'll have a problem. If you're worried about it, contact Raxles for their high performance version.

sn95_331_GT_ yellow

03/04 has the 31 spline, 01 is still the 28 BTW

my 331 is getting the 31's but only because i got an 03...

S351R13

You won't see much benefit with the IRS. I tried it before on the road course and swapped back. Your spring and shock combo make more of a difference with a Mustang.

sn95_331_GT_ yellow

in it more for the uniqueness than the "performance" upgrade.

if i wanted the end all id get a panhard bar/torque arm set up and show every other IRS car (Vette, Porsche, etc) nothing but tail lights.

having IRS is only something ive ever seen once before on a round (94-98) SN95. seen it once on a fox as well. seen it about 8000 times on the New Edge Mach 1's though...

so i want it just to be different.

.boB

The improvement in ride quality is amazing. My '08 Mustang had a harsher (stock) ride than my Cobra with IRS. I thought Ford really made a mistake in using a solid axle.