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So after months of trying to get information (or lack of it in my case)on carb conversions (mine was converted by previous owner), I have decided to put the original injection back on. The engine is a 1975 4-bolt main L82 - cam unknown. So the QUESTION is: what is the best procedure and products to insure the intake is sealed properly.
p.s. Also if someone can recommend the best performance street cam for a stock TPI intake engine
I would check and ensure that your heads (I don't know what's on your engine) are compatible with the '85 L98 intake manifold bolt angle and pattern. As you probably know, some iron heads have the intake manifold bolt going vertical into the head rather than at an angle.
The procedure and products are covered really well in this post by several of us when Kenlou recently resealed his '86 intake manifold. Opinions will vary, but I've had good success using the FelPro L98 intake manifold gasket set (blue silicone version), GaskaCinch, Permatex PTFE Thread Sealer, and The Right Stuff RTV - in regular squeeze tube format not the pressurized can version.
While you're putting this all together, consider doing what I did with my 85. I had the intake apart to paint everything the same color as the car, and I added a strip of blue LED's under the plenum. With the intake manifold painted silver, the blue reflects off and makes that engine glow! Nobody else has this on an engine, and at a show-and-shine, it will actually drag people over to have a look at this cool engine. It's a great talking point!
How can the cam be the same for an 84 and 85. Completely different engines. Vader 86, what do you mean "do the chip". Are there services like FROST that program them?
How can the cam be the same for an 84 and 85. Completely different engines. Vader 86, what do you mean "do the chip". Are there services like FROST that program them?
Completely different? They are both smog era 350s. About the only major difference between the two engines was the intake manifold. Quick search through old forum posts reveals the stated specs for an 85 cam and the stated specs for an 84 cam are the same. 1984 (I also measured and can confirm these specs) 1985 (which references the PN being the same for 84)
How can the cam be the same for an 84 and 85. Completely different engines. Vader 86, what do you mean "do the chip". Are there services like FROST that program them?
Cam profiles are not all that different for any L98, but 84 and 85 are basically identical except for TPI vs Cross-fire intakes.
Once you change the camshaft, the timing tables and fueling in the stock programming are not adequate to feed the engine. You will not get the most power gains out of the cam without the programming, and you can have 'dead spots' or 'rich spots' in the RPM band. Once you go more than a few degrees of duration off the factory cam, you start running into these issues.
The chip must be removed and somebody has to reprogram it for the new cam. Its best to do this with a dyno but there are mail-in people, but 85 is unique because its ECM is unique and less capable than the 86-91s. Not many can do an 85 chip.
85 stock intake
