Ok my heads are in and my 350 block should be out of the shop tomorrow. Been a very great day!!

Well any-how I also bought HSR and looing at it I cant seem to figure out they the hole in the bottom of the plenum between the runners is for??

I have 4 vacuum places in the back and Holley shows them on the docs and where they want them hooked up.

THEY SAY NOTHING ABOUT THIS taped hole in the bottom center of the plenum.. What is this for

Oh yea my cam, lifters, rockers, springs, toque converter, EVERYTHING came in today.. It is like a PARTY!!!

Sorry just to happy.. I am still wondering what the taped hole is for.

 

Ohh I also found the charger to my digital camera today so I can post a pic if that helps. Wow this really has been a great day!! :lala:

 

the hole on the bottom of the intake plenum, in between both sets of runners is for you MAT (also called IAT) sensor.

 

Thanks

 

Do not bother putting you IAT in that plenum, it is one big heat soak. By moving it into the air intake tube I saw a 20* temperature drop on an average summer day.

 

I use the hole in the bottom for the PCV valve hose. This way it evenly distributes the oil vapors to all cylinders, rather than the back two.

 

I was running the PCV from that location untill I had to change the intake gasket. When I pulled the HSR apart I saw how much oil was being sucked up into the plenum and then down the runners, it was a considerable amount. So I did some research and found that PCV only needs 2 or 3 inches of vacuum. I was running it at full vacuum.
Needless to say I do not have PCV at the moment. I think you might also find the like.