Lots of debate as to why the coolant lines were designed to be there in the first place. Some say to cool the components from the exhaust gas. Some say to heat the throttle body to prevent icing under certain conditions. If you think they're there to prevent icing, some people remove them in the belief that it will result in a cooler air charge entering the intake which could theoretically allow more HP. I think it's probably 'much ado about nothing'. The HO's had them; the Cobra's didn't. Both had internal egr systems. I doubt there's a significant benefit to removing them if they're there.