My motor is a 72 Stage 1 that will be getting a set of TA Stage 2 SE heads,as well as an SPX intake. I have looked through the TA catalog and there are several thicknesses of intake gaskets. I will be using a AM&P valley pan on this motor.With the heads and intake on the motor,the gap between the intake and heads is over.080 but I don't have the head gaskets on at the moment. How would I determine which intake gaskets I'll need then??
You'll have to find a way to mock it up (old gasket or ?) and/or predetermine where it needs to end up at. You can't do it with every engine, but I prefer to raise the head port up to the intake manifold's roof whenever possible. (I'm basing that preference on using a flow bench as a tool to reach a power goal and the near certainty of raising ports always helping things...vs unneeded milling to make things fit. Your priorities and solutions might be different)
I usually just mock it up with new head gaskets and do not torque them down, I then fit the intake and use some plastic shims of various thicknesses to see which thickness will give a good fit.... I use feeler gauges to find some plastic the right thickness. Then I order the custom TA intake gaskets in whatever thickness I need.
I just installed a SP1 last weekend however I did not have the heads removed. The SP1 comes with pretty good instructions and I followed them exactly. I had a set of 0.032" gaskets from TA Performance and a set of 0.0.60" from FelPro. Ended up using the FelPro but I could have probably used the ones from TA Perfomance. Here is why. I had to tighten up the bolts (not a lot) towards the outside of the manifold in order to get the angles of the bolts at the center of the manifold to line up. I hope that makes sense. With the bolts to the outside of the manifold being finger tight, it threw off the geometry of the bolts in the center and I could not thread them in. Other than that, everything was completely straight forward. After I got those center bolts (4 total) to line up I torqued the manifold accordingly. I haven't had an issue yet. I used this torque pattern from Edelbrock - Page 2. http://static.speedwaymotors.com/pdf/3252515.pdf From what I gathered on the installation, the most important thing is to make sure all of the geometry lines up good to ensure a very good seal. I would buy various thicknesses, mock it all up until you get the correct fitment.
I've always found that the easiest way to choose intake gaskets prior to final port matching is to find a previously used set of head gaskets (the same type you plan to use) to mock up the cylinder head to the block - which was previously mentioned, and torque the heads down with used gaskets. Then, once you drop the SPX intake into place, you can use paper, cardboard, feeler gauges, washers, etc. of the same thickness at all four corners between the intake and heads, while using a flashlight, or better...a scope to see how the port alignment is looking. The cool thing about the SPX is that you can see two of the four sides of each port looking down from the carb flange. This gets you close, hopefully enough to help you figure out which intake gasket thickness is best. Next, go ahead and purchase the composite gaskets that are closest to what your shims tell you are best. Torque the intake down with your new intake gaskets (on top of the mock-up, the heads that are already installed with the old head gaskets) Have a look and see what you can see from the plenum. Then, remove the intake manifold and examine the new intake gaskets on both sides for indentation. You'll see it on the cyl head side of the gasket, and you'll see it on the intake side of the gasket. Then, it's up to you to modify maybe all of the three players...the head, the gasket, the intake manifold - for the alignment you'd like. Devon
What you'd like to avoid is seeing a "step" on the cyl head side. In other words, when at all possible, the intake manifold and gasket opening can be a little bit smaller than the intake port on the cyl head, but never the other way around. Also, modify the composite intake gasket to match the intake manifold so that no part of the gasket is hanging over into the airstream. Devon
