(6) 3/8 – 19 JSPT Straight Plug
(2) 3/8 JSPT Shouldered Plug
(1) ½ NPT Plug
(2) 28 BSPT Plug
This plug kit comes with all the necessary plugs for a stock or Offenhauser intake manifold. The picture below shows an Offenhauser manifold with the plug locations. This picture accounts for the most common plug locations. We also include a few extra 3/8” JSPT straight plugs. These are sometimes used in the thermostat housings and/or stock manifold applications. You will notice that there are two different types of 3/8” plugs, a shouldered and a straight. There are two holes that need this shouldered plug to seal. If you look on the picture below you will see that there is a “step” in the hole that the shoulder seals on. If you use a straight plug on these holes it will not seal properly.