Ok, so I searched all of the post on p&p and didn't find the answer to my question. I am working on the ln2, and my question is about the exhaust ports. There is a ridge cast into each of them in the middle of the port. Do I grind this out smooth?? I know from prior port jobs on sbc that you want the ex ports really smooth to prevent carbon build up. Do do I remove the ridge or leave it? Thanks guys.

Ah, very good question. This has been debated for years, but the majority of people say to leave it. Polishing it won't hurt, but it seems that removing it may greatly affect exhaust velocity. The later years '98+ had smaller ports w/o the hump to help increase velocity. I'm hoping to have a head flowed later this summer with the bump removed vs w/ it in place.



fortune cookie say:
better a delay than a disaster.

The vane in the exhaust runner is there to increase the exhaust gas velocity, helping it to make the transition aroungd the short side radius and transition into the exhaust manifold/header. This primarily applies to N/A motors, a boosted motor may or may not see a gain by removing this vane. Leave the vane in there, if anything just smoothe the surface of it.

Thanks for the info guys, much appreciated. I have a couple heads lying around, maybe ill take the bump out on one and have it flow tested against one with the bump in. I'll keep you posted, thanks again.