Getting ready to purchase a new exhaust system for my 59 394. I would like to convert from the original single system to dual etc. I noticed the manifolds were orig set up for the single with the cross over pipe etc. Does anyone know if the 1959 394's used different manifolds for the dual systems? Or do you just block off the fwd side of the pass manifold (plate?) and use the same drivers side? The hollander interchange throws me a curveball by stating 1959 uses only one for both sides, which can't be correct. I'm sure I have the originals which came with single exhaust. If there is simply a plate added, is there an original type? Not sure the drivers side can work as it dumps straight down (cross over) rather than angling to the rear. As I type this I can't remember my exact numbers but I believe they are 573324 and 573325. I know the last 3 numbers are correct. Without driving the car to an exhaust shop to custom fit etc, it's a little risky to order abroad with these open issues.

 

My 59 parts manual only lists one style manifold for the 59 V8 573324 and left side 573325 The blockoff plate on the passenger side is just a flat piece of triangular metal about 3/8 inch thick and will take a gasket. Duals are kinda weird on the 59 as they pass thru the x frame and driver's side header pipe is flattened almost half the diameter for clearance. Resonators almost mount vertical at rear axle.

 

rarebare, will you please drop me an e-mail?

I'm in Puyallup, and we've planned a few 1959 GM events during the last few years. Would like to connect with you and plan a get-together when you have that fabulous '59 Ninety Eight back on the road.

brianL@americanconstco.com