The attached graph shows flow area increase with the auxilliary ports open.

Can anyone tell me how happy I will be with the performance gain when I get the aux. ports to operate properly? What have you experienced?

84 GSL-SE purchased several months ago. I discovered the main cat missing, so no back pressure connection was available, and the actuator line was connected to the vacuum circuit.

Presently have manifolds off - one of the valve connecting rods was frozen tight and I had to hammer it out to get it clean and free.

 

it should pull hard to 6500-7000 with the ports open, instead of falling off around 4500. no main cat should actually help a little