[cmitchell17]

Was anyone able to confirm the true differences between the ZL1 and SS systems?

So from what I am seeing it seems switching to the ZL1 part number primary cat it should bolt up? but I guess we are still doubtful it has any extra airflow capacity over the SS part number.

I have compared a lot of the SS and ZL1 part numbers and see that a lot are different and I just don't get why GM wouldn't try to save on costs with the same PNs for both if there is actually a need for different parts so they could meet their power goals for the LT4 over the LT1.

[Bumbleboy92]

Difference wise I believe the only difference is as someone said of larger piping and larger tips.

I put a axle-back from a ZL1 on my v6 so it’ll fit lol

[Spartan268]

Originally Posted by cmitchell17

Was anyone able to confirm the true differences between the ZL1 and SS systems?

So from what I am seeing it seems switching to the ZL1 part number primary cat it should bolt up? but I guess we are still doubtful it has any extra airflow capacity over the SS part number.

I have compared a lot of the SS and ZL1 part numbers and see that a lot are different and I just don't get why GM wouldn't try to save on costs with the same PNs for both if there is actually a need for different parts so they could meet their power goals for the LT4 over the LT1.

So from what I found back when I made the thread and the shop I went to, who took it from their ZL1 shop car. Airflow is negligible, asides from the headers, this car has very good airflow from the cats to the back. You can be FBO and you're not leaving much power on the table with a stock catback if any at all. Some top quarter times are with a stock catback. If you're talking about the cats, I wouldn't waste your time on the ZL1 cats and just go straight to some High Flo's or catless pipes.

But yes the shop made a similar remark about the cats being slightly off. Thankfully the exhaust I got marrys up to the secondaries instead so no fitment issues there. Come time for headers (Which I might regret with the Ataks) it should be a good fit.

Did you have some specific plans in mind or just wondering?

[cmitchell17]

Originally Posted by Spartan268

So from what I found back when I made the thread and the shop I went to, who took it from their ZL1 shop car. Airflow is negligible, asides from the headers, this car has very good airflow from the cats to the back. You can be FBO and you're not leaving much power on the table with a stock catback if any at all. Some top quarter times are with a stock catback. If you're talking about the cats, I wouldn't waste your time on the ZL1 cats and just go straight to some High Flo's or catless pipes.

But yes the shop made a similar remark about the cats being slightly off. Thankfully the exhaust I got marrys up to the secondaries instead so no fitment issues there. Come time for headers (Which I might regret with the Ataks) it should be a good fit.

Did you have some specific plans in mind or just wondering?

Thanks I was just wondering, I know the OEMs don't like having multiple part numbers, I'm wondering why they needed 2 different ones.

[oldman]

Originally Posted by Bumbleboy92

Difference wise I believe the only difference is as someone said of larger piping and larger tips.

I put a axle-back from a ZL1 on my v6 so it’ll fit lol

pipe is NOT larger. one cat I think the driver's side is slightly different, and the tips.