When did the dual catalytic converter exhaust setup appear?

What cars was it standard equipment on?

What exhaust setup would an '89 Iroc L98 come with from the factory?

Oh, and are all Iroc wheels 16"?

Thanks for your help.

 

On the 16" wheels the '85-'87 IROC package(RPO-B4Z)came with the 16" wheels(either in gold or charcoal).When Chevy trimmed the model lineup down in '88 to SC/RS and IROC the 15" 5 spoke aluminum wheels became standard(as well as the TBI 305 I believe)on the IROC.
The dual convertors started in '89 but weren't standard with the L98(as far as I know or have read).You could get it with The LB9 and L98.But according to "Camaro Whitebook" (as we know not 100% right at times) starting in '90 the dual cat exhaust was standard with RPO-B2L.A '89 IROC could have either one.But again I'm going by what I've read from different sources and what I've seen.
Hope this helps and not confuses.

 

No, that definitely helped, thank you.

Another question: were Irocs equipped with drum rears as standard equipment? How well of a braking job do thirdgen drums do, compared to discs?

 

You are most welcome and I'm glad to be of some help.
Drum brakes on the rear were standard all years with discs as an option.The disc brake RPO-J65 (my '83 has the J65 option along with G92 and G80).The drum brakes are RPO-J50(with some years getting aluminum drums).It's interesting there was a recall on the brakes from people complaining of high pedal effort in the all disc setup.Chevy's repair solution was to use the J50 power booster.
Drum brakes are ok with quality shoes but have a higher tendency to fade in repeated hard use.They are harder to modulate.What's fun is driving a car with 4 wheel drums(think of driving a car the size of a 4 door '65 Belair).

 

Bull, I don't remember if the dual cats came standard on the '89 IROC L98 that I ordered new in Germany. But it seems I had to specify a separate option package or RPO to get that set-up. I know I had to do so for the stripe delete and a few other things I wanted. I didn't have 4wdb, so I'm confident that rear drums were standard.

I drove all over Germany in that thing, and brake fade could be a problem from a 140+ mph stop. But it was a better than my '80 Corvette that had 4wdb. If not better, at least more predictable.

Why my LG4 '85 IROC that I own now was ordered with 4wdb, beats me. It surely isn't fast enough to warrant them ...

 

Thanks for the info, guys. So basically, drums are fine unless doing some seriously aggressive driving...cool.