Hello, I have a 1988 pontiac firebird formula with the six cylinder but swaped it and put in a Chevrolet 350. I was wondering if anyone knows where i can get headers to fit in this swap. Thank you.

Welcome aboard thirdgen.org.

You need 3rd gen f-body V8 headers. The header sticky has a bunch of information. Best bet, IMO, is either Hooker 2055HKR, or get in touch with TGO member Dyno Don about his custom made headers.

thanks I just didn't know if the chasis or anything is different from a 6 cylinder to 8 cylinder pontiac formula

I have both V-6 and V-8 Firebirds and the chassis is the same on both cars. However...the cars will differ from the engine back in terms of block length, motor mount position (obviously), manual vs automatic and the resulting cross-member. All of this complicates things slightly, but as posted above Hooker 2055's or Dyno Don's customs and with some slight prodding, bending, cursing, suitable beverages, etc....they will install.

Transmission mounts are the same V6 or V8, so the crossmember doesn't change.

The front crossmember is also the same, only difference being the location of the chassis side engine mounts and front brake line routing.

Chassis is same V6 or V8. Exhaust routing is the same. Some slight bracket differences such as the cat support mount that bolts to the back of the transmission and cat.