[pneall]

Rebel,

I think the issue is the side pipe design.....just not as good as a properly designed under car system with cross overs and equal length pipes....at least at part throttle applications.

However sidepipes do sound great.

I would have a look at the LS1 site to see what works but suspect 1 5/8 may be sufficient for a standard motor but larger may be better if you plan a cam.

Losing low down torque isnt a big deal as the Cobra is very light but you may notice it in 6th gear with the diff you are running.

Regards,

Phil