I currently have my 3" cross over pipe going into a 3" exhaust cut out and then into a catalytic converter that appears to have been blown from 2 1/2" to 3" at both ends and then to the muffler. could this be why on the dyno I get about 35ft/lbs more torque with the cut out open? the cat from what someone told me looks like it 's made for a 4cyl honda or similar vehicle. it's very small.

i was looking at this cat cmx converter

and this muffler vortex muffler

so I would have 3" cutout/3"cat/3" muffler and then just a 45 degree bend in front of the rear axel.

any opinions or other suggestions?

thanks
Jeff