I need to get one not sure of the size though.

 

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3/8th 16 is the correct sized tap (just ran one through a second ago to be 100% sure)

 

And I thought I was the only one messing up the threads on these 23 degree TrickFlows. I think their aluminum just sucks. I stripped like 5 of the holes so far.

 

Thanks guys....I will pick one up today, for some reason I had a problem with just the outer holes. I think I can clean them up with just the tap.

Yeah...I dont ever remember having a problem with threads in a cast iron head.

 

Check the hole depth where the threads start at. Some heads the threads dont start until about 1/4" down from the intake face and really for those you need longer bolts at the 4 corners of the intake.

 

Hey Madmax thanks for the tip, I tried a 3/8-16 NC tap it doesnt seem to be the right size for my Trickflow heads didnt want to force it. If its the right size it should go thru a good thread pretty easy right?

Thanks

 

I'm 100% sure that intake manifold bolts (and exhaust threads and a plethora of other spots on the engine, but i digress) are 3/8-16. Thats the only thread i own a tap and a heli-coil kit in, thats how common it is.
Are the heads already onthe car. Might be a good idea to just heli-coil 'em all if you're whacking a bunch of 'em anyway. I think thats how edelcrock supplies their heads (all holes heli-coiled)

 

Yea, they have to be 3/8-16. Must be messed up pretty good and thats why youre having problems getting the tap in there. If youre really good you can get the tap in there without messing up the threads, but chances are you'll end up having to helicoil it.

 

The 3/8-16 was the right one... They all cleaned up really good. I was just turning it by hand doing a quick check and all the crap in there was the problem. After I cleaned them up some, smeared a little oil on the tap, and used the tap handle it worked fine.

Thanks again!