Or if theres some weird looking metal thing with a pulley sitting on top of or near the engine.

then it likely wouldn't be a L36 :P

True It wouldn't fully be with the heads and stuff on there unless its csc'ed.

Mike, I changed my DP to a 3" before the headers. I noticed a decrease in low end. No doubt. It takes a lot to outflow your stock 2.0? downpipe. I say 2.0? because the inner diameter is closer to 2.0" than 2.5". I haven't precisely measured though.

The difference from what we call a 2.5 DP to a 3.0 DP is really nearly a full inch.

I'd say stock is about 2.25" if you account for the sleeve.

I think a built L36 should have long tube headers with small primaries and 2.5" exhaust the rest of the way back. That would be the ultimate exhaust setup on my car.

I played around with formulas, a couple calculators, and contacted a local gn shop about pricing and dimensions. For a higher reving L36 you would want the primaries to be about 30-33" with a 1.5" diameter. Since my headers were destroyed, I am going to make a set like this.

Mike, that would kick a serious amount of @ss. Boy, I wish I could do a set of headers right now! I hope you can do all the cool stuff you're planning on your next 3800 build.