Billet Plenums

[vr6nutt]

So I may be in a bit of a pickle, but am not quite sure...

In the middle of final assembly of my motor. Got a set of heads from a vendor here to use on my 03 build. Was beginning installation of the billet plenums from Riff Raff and noticed a peculiar difference. All but two holes line up on the plenum to head. Compared it to my old heads and spotted the difference. The rebuilt heads only have 8 bolts on the intake and my old heads have 10.

For comparison..

New:

Old:

Did some research and found that the heads are supposed to be identical, less the number of bolt holes. Are there any advantages/disadvantages to the different designs? Why did Ford change to the 10 bolt design? Boost leaks?


Already thought about exchanging the plenums but read that they're not for 8-bolt intakes - and they're back ordered. But 8-bolt is what I have now! Really want to finish up this build.

So this is what I am thinking...Being these plenums are rather thick where the bolts are, I am debating on tapping the two holes and sealing them up with a flush-mount bolt and a dab of some Ford RTV on the rear where the o-ring slightly misses.

Thoughts?

 

[TyCorr]

If you are going to negate the o ring, negate it entirely. Glue it all day or dont at all.

 

[gnxtc2]

The 8 bolts heads are early heads. The 10 bolt ones are later heads.

Billy T.
[email protected]

 

[vr6nutt]

And to further complicate this assembly, you'll notice that the oil galley plugs have been painted courtesy of machine shop. I already removed paint off the intake mani and exhaust mani areas as well. Any suggestions in removing the paint from the threads? I dont imagine I can leave it that way.

 

[Arisley]

Get a tap and chase the threads. Oil the tap well to pick up the shavings, back out and clean the tap often.

 

[Krause]

I would send the heads back and get the right ones. You must have told them you were building a 03'? The 8 bolt heads werent used after 95 as far as I know. You have 300 dollar plenums that utilize an oring, dont give up that hard paid for option because someone sent you 8 bolt heads. If you try to make it work, I feel like it's going to turn into a leaky hackjob.