I got the Y-pipe and cat delete from mac for a 99Z. These are the ones that bolt up to the stock manifolds. Anyone know the bolt size for the manifold to y-pipe. Its were the 2 1/2"collectors go. Think there a standed size but the places around here don't know. MAC tech told me to call the dealer

Went to the MAC web site to see if they had a brakedown of parts needed for instillation of there product. Nope but they have a garage talk for questions like our forum, just sign up. After you sign up and go back to post your question it informs you only tech and modorators can post

You would think MAC would be able to furnish a list of parts need to install THERE PART on a specific application. Not like this is some kit car or some weird hot rod.

Could also use the plug size for a o2.

Thanks I fell better.