Ok so I have a 1992 Z with a 96 vortec motor in it. ( I was told that when I bought it. it was a L98 car to begin with) the car is the vortec lower base intake from SDPC on it. I want to put on slp runners and a plenum that have been port matched to each other. I want to port match the base to it also but I have never done anything like this. what needs to be done. I also have to match the gasket to the intake and etc. how hard is that? any info is helpful.

 

It sounds intimidating, but it is actually very easy to do.

When I bought my car (I am the 5th owner) I soon discovered that one of the previous owners had installed SLP runners, but didn't do any port matching. Since this defeated the whole purpose and really irritated me, when the original 305 that was in the car went to SBC heaven and we had the intake disassembled installing the new 305, I decided it was time for a little upper intake improvement.

First thing I did, was seriously douche the plenum with degreaser and scrub with a wire brush since this thing had become NASTY on the inside over the years (take a look inside and you'll see what I'm talking about. No that isn't paint...).

Next thing I did was resurface both runners and about 90% of the plenum, with the exception being the bottom half since this area isn't visible once on the engine and won't mean a whole hill of beans. This was the longest part of the process, and took approx 3 weeks between work and family.

The next thing I did was pick up a set of felpro gaskets and (I know this sounds silly) port matched them to the SLP runners. I then put them on the plenum as a template and port matched the plenum, siamese included, to the runners.

Last but not least I painted all three items with high temp paint and it turned out pretty good.

For tools, i used a sharpie marker, sandpaper and a dremel tool for all the porting. For the port work on the TB and runner ports, I used all sanding drums. They wear down fast so be sure to pick up about 10 of each pack (I roughed the surafec with the 60 grit drums and smoothed it out with the 120 but if your not gonna resurface this step is pointless)
, but I think they allow for a much more accurate and cleaner port than a grinding stone would.

I also ported out all the "blocks" GM put inside the plenum. This step is a HUGE PITA, but with some patience, a flashlight and a couple reinforced cut off wheels that have worn down a bit, It's possible.


Some people here would say that resurfacing from scratch to finish with a dremel tool is pointless, and to use sandpaper and a sanding block. This method provides a smoother and more even surface, but takes much longer and wears your arms out quick.

The dremel takes it right down right away, with the drawback being a little bit of extra time must be invested because it resurfaces uneven. With some areas being deeper/more removed/more scratched than the other. It's pick your poison, but the dremel made it seem a bit easier for me before finishing up with sandpaper. Be sure to plug your nose if you use the dremel as the aluminum smells awful. Ever been wondering through the woods as a kid and come across one of those creek swamps that had the slimy black stuff lining the shore? Yeah, It's that bad...

Easiest way is to use a poer sander and the dremel for fine areas, but I did not have a power sander so I cannot attest to the difficulty level of it...

 

well the runners and plenum have already been port matched to each other. I bought them from a friend that ported them. I can't use his base though cause he car didn't have vortec heads. I want to port match the lower vortec base to match the plenum and runners.

 

Check out my sticky thread at the top of this TPI forum: "Quest for a better flowing TPI." We outline the details on how to make a TPI intake perform better.

Also search for my post on "Visual TPI intake ports." I show the areas that are the trouble spots. Open up the area by the injectors when you're port-matching the intake to the heads. That will give you a greater benefit.

 

Alright there David, Hey you can just put those runners and plenum on without much porting. The intake in an Edelbrock vortec intake which is larger than stock, which runners did you get ? Unless they are TPIS runners then they will be close already to your vortec intake manifold. You got a deal on my old car , did you not know it was a 96 motor?

 

They are the SLP runners. Yes I know its a 96 motor. I know I got a deal and I love the car.