|
IMO, I would get the headers first. This is where much of power can be freed up. Stock exhaust manifolds are unevenly joined at the collectors causing for disruption of flow. With the headers in place, the flow of exhaust is evened out. If the headers are coated, that will cut down on engine bay heat thus causing better engine performance. Moreover, since the headers are mandrel bent, this does not cause for exhaust turbulence which can cause for an even bigger loss of horsepower. As for cat or !cat... if you switch to a "high flow" cat or stay stock, your not going to see that big of a difference. However if you do i-pipe and muffler work, it will help the overall aspiration of the engine. For the 5.7L LT1's, I would do a single 3'' I pipe (mandrel bent) into a _________ muffler (don't know much about them there fancy mufflers, you'll have to do the research yourself. Though, I never had a problem w/ my 80 series flowmaster).
|