I would do some insulating and add out the back turn down tailpipes. I would use 2.5 tailpipes mandrel bent. The exhaust has cooled enough by the time it's made its way through the mufflers for the 2.5 tails not to hurt you much. The F. A. S. T cars do it through a full 2.5. That along with the 3.23 I believe will fix you if your converter is tight enough.
This.
Fix the exhaust first. The 2 1/2 tails will be quieter and might actually make as much or more power as 3". If there is room you could add some straight thru bullets in the tailpipes to make it even quieter and help eliminate possible drone problems.
If you want to try some converters I have 11" out of a 69 Superbee and a never been used 10" Fairbanks that is old enough that it was probably built by Lupo before he started Dynamic.
