What's the difference between 1-piece and 2 piece? is one better then the other?
thanks

 

I perfer the one peice because it would be one less possible leak.

 

agreed

 

That and better chance of undisturbed airflow.

 

ok thanks. one more question, which is better, 4-2-1 or 4-1 ???

 

421>41 for low-to-lower-midrange, 4-1>421 for high midrange and beyond.

 

Well a 2 piece is (in most cases) easier to install than a 1 piece. A one piece you really have to wiggle and wiggle to get the header in sometimes, whereas a two piece you attach one part to the block then the 2nd piece to the 1st.

Flow on a one piece is better of course so you should get 1-5 more hp.

 

headers actually cause a gain of horsepower????????

 

The first header does. Additional headers dont give any more gains.

 

The 2nd header gives you a smile when you stuck in traffic.