What is the center to center spacing between the exhaust ports on the LS1 headers in inches. Thinking about buying some BB vette headers and welding new flanges on them.

 

Make that 2 of us that want to know... Just eyeballing they look similar but looks can be deceiving...

 

I just measured a set of BB headers, they are 5" exactly on center.
And I just measured a set of LS1 heads, exhaust ports are 4 3/8 on center.

you might be able to shorten up some tubes on the BB headers and make them work.
Im sure you could.

 

I used BB Patriot Clipsters on my Monte Carlo SS. One tube was in the correct location and just needed to be welded to the LS1 flanges. The other three tubes, on each side were easy to modify.

 

got any pics of those headers?

 

The bb headers ended up not working. The back port would never line up without having to remove the collector. I ended up buying a Speedways kit for $150. They now make a LS1 kit.

 

Just in case anyone else is looking for this info, an RX7 guy took some 5.0 headers and swapped GMPP LS1 flanges on them without too much hassle. The exhaust port spacing is either the same or very close to an LS1, so it might be another option for someone else.

 

actually the rx7 guys are using a 'fox body' mustang(79-93) header; BBK makes a 351w swap header for these that is 1.75" and lines up well on the LS1. it can only be used with a manual trans, though.