okay... I have an 01 Z28 / LS1 of course....
I was offered a set of Ceramic coated Hooker Longtube Headers with 3" ORY Pipe for $200 with about 5000 miles on them. I know it is a great deal, but I need to know this:

Without using the ORY pipe will the LTs hook right up to the stock Y pipe to keep the catalyctic converters in it? The headers looked like they already had the O2 sensors on them as well. Collectors were already there as well....

What questions do I need to ask this guy to make sure they are the headers I need for the Z?

 

no, you'll need the ORY or another Y pipe made for LT's. you cant use the stock Y and whats the point of keeping the stock cats. they flow like **** anyway, the point to upgrading the exhuast is to keep it free flowing, not one free flowing part and then restrict it off.

you'll need front o2 extentions and an ORY to make the headers work, provided there the 01-02 headers. if there not you'll need to adj. for any egr/air provisions.

 

so if they came off of a 1999 Z I will have fitment issues?

 

got offered Hooker LTs with ORY Pipe and I think it came off of a 1999 LS1. Considering I am an 01 F body, will I have fitment issues with these? O2 sensors etc etc? or will they bolt right up

 

If they were on a '99, they will fit. '98-'02 are the same. The only difference is the EGR provision on the header, but that can easily be blocked with one of the custom fabricated parts out there!

 

You'll have to either get a set of 98-99 AIR tubes, bend your stockers to work, or take the whole AIR system off. You'll also need a block off plate for the EGR tube on the headers.

 

I merged both your threads asking the same question