Hi

I'm doing a little resarch for my engine swap. I have the intension to use a 5.3 (LC9) engine and tune it a bit (52cc LS6 heads (10.7:1CR) , LS6 cam and springs).

If the 6.2 Headers are bigger, I'll prefer them of course. But if the catalysts are also bigger, I'll run into space problems.

 

Generally headers are classified in size by primary tube diameter... and not the size of the engine. For a 5.3L with an LS6 topend I would go no bigger than a 1 3/4" primary. I would also go with a long tube header such as what Stainless Works makes.

Bill

 

Right, my bad. let me refraise my question: Do they use different headers on the 6.2 in the same vehicle than on the 5.3 in support of the 6.2's 400+ HP.

Most unlikely to pass the strict emissions test after the Swap. They eyes of the tester are the problem, not the OBDII or sniffer probe. Head and Cam will be done after the Swap. Which is allways easier to do at a dedicated Tuning Shop. Read: Not Engine Swap Shop