Speed 5183 Low Profile Aluminum 3/8" NPT Vacuum Fitting Tee

I bought this product thinking it would fit flush under my carb like the Demon carb picture on their website. The way it's supposed to fit in order to clear the rear of the carb. Unfortunately it only threads half way into my Edelbrock air-gap intake manifold. I called Speed Unlimited but they could not give me an explanation why the thread length is longer and tapered at an angle where it gets wider towards the top, making it impossible to screw in all the way flush with the manifold. According to both Edelbrock and Speed Unlimited, neither one of their products have compatible threads for a simple vacuum port on the back runner. I'm already frustrated from calling both companies trying to find out why they can't make compatible threads. Edelbrock's pipe plugs and fittings at least are the correct threads and length. Speed Unlimited's fitting is tapered in such a way that the top threads are 1/16" wider at the top. Of course it is, hence 'tapered thread', but no explanation why their part forces customers to have to re-tap their intake manifold. Even if the threads on my intake were tapered as I was told, the length does not match. "Of course it won't thread all the way down, it's tapered thread" they said. So why would you sell a product that doesn't do what it's supposed to do? Fitting flush underneath the rear of the carburetor like the one in the photo on the website! I was told "other customers use professional intake manifolds with no issues with the fitting". Still I can't understand why they make their products incompatible with one of the most common intakes 'Edelbrock'. Had their thread would've been the correct length and diameter as the plug I removed which is an exact match to their Edelbrock pipe plugs and fittings there wouldn't be a problem. I constantly measured with a caliper and see inconsistencies with the length and diameter on their fittings versus Edelbrock's pipe plugs. The end result and my only solution is to either buy a fitting from Edelbrock or thread the intake deeper to compensate for the extra thread length on the Speed Unlimited fitting. Buyer beware.