IAT on '88, thread pitch for plenum swap?

[RoadWarrior222]

Hi folks,

Can't seem to find the plenum swap page that had the details for the IAT thread pitch needed to put the '88 IAT in the new style plenum.

I seem to be remembering that it was 3/8 NPT, but not sure. Measuring it seems to give about 11/16 diameter and 16 tpi... not a lot of thread to measure across so hard to tell.

Also anyone done a new plenum onto old lower? and what did you do about the PCV?

Figure I really need to get the new plenum on soon, want the torque @ 2400 instead of 2800, figure it will help on gas...

Was gonna wait until the '92 motor was ready, but it's gonna be a long while for that, and need to do something soon.

thanks,

RW222