I just swaped a GSR head on my LS and the 4 to 1 exhaust headers I have (for the LS head-Strup)are just barely touching my oil pan. I trimed the back bracket to help them fit. The flange still mounts flush on the head but the headers just barely touch the back of the oil pan.
Here's the options:
-Use heat wrap around the area close & touching the oil pan.
-Switch to stock GSR headers and get a 6 inch pipe made to match up with my current exhaust.
-Get my 4 to 1 headers modified to fit.

You can imagine I want to go with the first option as it's the cheapest and I still get the little bit of HP from the headers. I can get the GSR headers for $30 and I don't know how much it would be to have the extra pipe welded on.

I plan on going turbo mid summer (3 months) so this is a temporary thing. Although, my bottom end is built and I don't want to toast it.

Info & feedback greatly appreciated

 

ohh yea...one more option- Heat up the headers and adjust them slightly with a hammer to make some clearence. (the stock GSR headers have only about 1/4" clearence anyways)

sweet now I'm talkin to myself