I know the suspension is different on the models and some IROC's have 350's after 87' and the wheels and cosmetics but is there anything else different? What exactly is different on the suspension, engine and trans?

 

Go to www.iroc-zpost.com and they should be able to tell you all the differences. Some of the differences for the Iroc are: springs are 1.5 inches shorter than a z, the steering is alot quicker, an additional brace (wonderbar) is mounted under the front end, sway bars are bigger, Bilstein shocks on the rear, 16x8 wheels with 245/50/16 tires, front ends have deeper air dams, side skirts. I have drove a z28 and my Iroc just feels better to drive. The suspension is what sets these apart more than anything, as any of the V8's could be ordered.

 

That is quite a diverse question. GM offered many different combinations so it will hard to give an explanation with out writing a book.




1985-1987 Camaro Z-28 (IROC was a 659.00 performance option for Z-28s) It included Lower trim height and center of gravity, Special front shocks, blistein rear shocks, a beefed up stabilizer bar, 16X8 rims, higher effort steering and a tweaked chasis.
For 85' engine LG4 made 165 hp (z-28 and IROC)
the L69 made 190 hp (IROC only and only T-5 manual transmission)

only 305 engines were available with both carbs and TPI(with the exception of 50 86' cars that had T-5s and 350s.

In 1988 the Z-28 is dropped instead called the IROC-Z
In 1988 a 350 became available in addition to the 305 but only with an automatic transmisson. The manual was limited to a 305. All were TPI

RS came out regionally 87 in 88' mostly as a california only car to replace the camaro LT, came only as a 6 cyl

1989 the RS was added to the camaro Lineup. The RS now offered a TBI 305 (LO3 170 hp) or a 3.1 MFI engine. Convertable RS only offers the 305 and offers no 6 cyl convertable)

However a RS could be ordered with RPO B2L (police package) giving it the 350 from the z-28 giving it 230 hp (auto only)

In 1990 the Z-28 returned half way through the year.

The IROC also had an option called 1-LE
which was triggered by ordering RPO Gu5 performance rear axle. When ordered with the a/c delete and radio delete a whole bunch of extra goodies were added like the swinging gas pickup

Well i tried to keep it short, i hope that helps