Generation III External Engine - Mac Collector Mod

Is it worth it? Is all you do is cut off the end of the collector, and weld in a piece of pipe to the y pipe? What is it worth? I did run a search, and didn't come across the exact info I was looking for--thanks!

not so much cutting the ball flange off as porting the primaries.

http://www.ls1howto.com/index.php?category=3&PHPSESSID=e6fd8450c85aed9cea305b27a168d275

I ported the primaries, definitly is a restriction there. I will do the collector mod soon. It's the bottleneck of my exhaust system right now.

Thanks guys. How much of a gain is it? I thought about going w/ some pacesetters, but since I already have these, I thought about just doing this.

Anyone?