i'm doing some bargain shopping, and see that thorley makes their tri-y headers for up to i think, '02 silverados, i'm going to install a custom exhaust, if so.... do you think i can get away with these headers?

 

I believe they can fit, but they are a different part #, e-mail the guys there, I inquired about them before for my 03 and I think thats what they told me.

 

They fit on my '02 but were made for 99-01's. All you have to do is block off the egr valve.