Thread: Tri-Power Carbs build.

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As the center carb is the one that the engine starts, idles and runs on for the majority of the time no internal mods are necessary or even desired.

If your using a large base center carb one of the things you will note is the fuel inlet is in the front of the carb rather than on the side as is most common on the small base Rochesters. While this may not cause a problem on some intakes on others there is no room to get a 90 degree fitting in.

When this happens I convert the carb to a side inlet. The first step is reasonably simple…. drill and tap the side of the fuel inlet/filter housing for 1/8” pipe thread. You will want the hole as close to the protrusion as you can get it so that the fitting you use will not cover up the screw that holds the top of the carb on. This makes it a lot easier to remove the top of the carb in car for jet changes while you’re dialing the carbs in. Simply install the fitting using a little red locktite and that part of the job is done.

The final step is to make the plug for the original fuel inlet. There are two common styles of inlet fitting a thick one and a thin one with a small nipple. Total thickness of either is the same. Normally I start with the thinner fitting and grind the nipple off. After that I drill the center hole and tap it for a 1/8” pipe plug which I install from the inside, then to insure there is no chance of fuel seepage I fill the recess on the outside with solder. Install the plug with the new gasket from the carb kit and you now have a side feed large base carb.

It should be noted that you can no longer use the stock in carb filter, but if you’re running a good inline filter it won’t make any difference.