This weekend i plan to tackle my LIM gaskets. So doing this raises a couple questions for you all. First, is the upper intake a problem like on the series 2? The reason i ask is because a couple mechanics told me i should change my upper intake when i do the upper and lower gaskets, but thats a $150 that i wasn't planning on spending for this project, especially when i haven't heard of too many problems with the series 1 uppers. The second question is if there are any mods i can do while i have this apart, like to either the upper or lower intakes, throttlebody etc. Hopefully you all can clear this up for me, Thanks in advance

the upper manifolds on the series I are better designed then on the series II and rarely fail seen 2 fail on this whole forum. most mechanics think they are the same. its not.

port and polish ftw

How long are you planning on having it apart? Smoothing things up some might help. You could gain about 5hp or so from polishing the runners in the LIM on an L27. Maybe 10hp at the most. A little more than an L36 because the runners in the LIM of yours are longer than an L36.

Shaving the shaft on the TB and countersinking the screws would help a little at WOT as well. Search for throttle body posts by me. I've done quite a few now. (I'm swamped and don't have the time to search for you, so maybe someone can post some links).

Other than that, there'* not alot to do while doing gaskets.

Do you have leaks? How many miles on these gaskets? Have you done a tune-up?

(L27'* do not have the problems the L36 does with the Upper Manifold, but your LIM gaskets should be changed at about 100k miles).

I believe they are original gaskets, and yes the lowers are leaking just a little bit. The car has 165,000 miles on it and about 6,000 on a tune-up. What is the best way to polish the runners on the LIM? Downtime is not a problem either. Thanks again.

Try searching on port and polish. Both words. In Performance and Brainstorming. You should find good links to all the stuff we use. Techinfo is a good idea also. Check out the supercharger porting and polishing there.

I've searched and looked through a lot of threads as I will probably be doing the same thing this summer. Could you give us some specific bits that you have used to port the LIM ports since you have the most experience and excellent results? IIRC you were using a Dremel and I would assume some type of carbide bit?

Wren was using a carbide Dremel bit... Standard issue.

I also have done quite a few and would suggest trying a sanding drum as well. Had good success with it. Then fiinished up the corners with the carbide where the drum couldn't do.

Sounds great, thanks for the info.