1974 firebird 400 exhaust size

[one409]

I am the original owner of a 74 formula 400 4-speed. I need to find out the correct exhaust header-pipe size. I have heard that all dual exhaust cars were 2-inch and only super duty cars were 2.5-inch. However, I thought that the 400 4 bbl cars were also 2.5 inches...can anyone help? Richie

[Larry]

Suggest you give Classic Exhaust in Ohio a call at 440-466-5460. Ask for Scott.
Classic Exhaust is a Featured Commercial Supplier of PontiacRegistry.com and will give you a 10% discount on the parts also. Remember to print out a Discout Coupon if you buy from them. Go to the "Commercial Supplier" listing shown at the left.
You can also check with Larry Cooper of Fabulous Firebirds who is also a Featured Commercial Supplier giving our members a discount on parts. Larry is also the Firebird Tech Advisor.

[Transamric]