I'm still looking for some visual help on this... I misplaced my plastic plenum cover screws when removing it to work on the car.
I can't seem to locate them now... I just need a nice digital shot of the screws in macro to help my search Thanks
BILL

 

If it helps I seem to remember that they are 3 buttonhead torx Head screws about 5/16" or 1/4" long...

 

I'd guessed they might match the others, but no dice as of yet. I may have to upgrade my wiring anyway, but along with taking this off, I had also removed the dome hood vent. I personally feel it offers more cooling then having it on, any thoughts?

Of course, I live in hot and cold extremes, and it has stayed off. I don't think it's effected too much as the engine does run somewhat hot as the 350 appears to
BILL

 

Dome hood vent...

Are you referring to the whole assembly, or just the block off plate?

I know by removing the block off plate you will force more air into your engine compartment. Any speed above 45 Mph the air is forced IN, not sucked out as one would expect...

I took some kleenex streemers and taped them to the top of the buldge, and at speed they would stick to the screen... pretty cool really ... Kleenex is really HIGH tech too

John

 

They're nearly identical to the screws in the TB plate. Take one out, and you won't need a photo.

 

I thought the Torx bolts in the distributor cover were more like a Button head/Round Head, whereas the ones for the Throttlebody was more squared off like a Machine Head...

John

 

Well, I did say nearly identical. The plenum ext screw also has a thin washer.

Other than that they're pretty much the same. Both screws are the same length. Should be enough to go on, I hope.

So take a TB plate screw, and imagine it having a pan head. I would think that would help more than trying to compare to a photo.

 

Bolt, Intake Manifold Plenum Extension
P/N 14083852
It is unique to this engine.

 

good time to upgrade to the vette alum extension as you need new screws for it when you install it anyway

 

They used Aluminum on the Vettes???

That would seem to be a bad choice... I would see where the ignition could arc to the Plenum... But GM knows best right?

John

 

I'ver been using the Al plenum over a year with no problems.

According to others on here, you cannot use the same screws from your old plenum ext if you go with an Al piece. No one every explained why though from what I can see.

 

Metal to plastic, no problem.

Metal to another type of metal, problem, thats what I'm thinking anyway, perhaps the Al version uses zinc coated fasteners ?

Don

 

That may be it... The Steel Screws could cause the Aluminum to Corode... BUT, the Plenum is Aluminum :shrug:

John

 

At speed the air flow hits the windshield and builds up, causing a high pressure area at the base of the window. Because the vent is rear facing it allows air from the high pressure area at the base of the windshield to escape into the engine bay which is relatively a low pressure area.

 

you need the aluminum cover to do this.....

 

That holds true for any fastener on the intake, which is why some have switched to stainless. It also looks better than the black painted stuff. I'd be happier if I had stainless stuff that looked closer to the original though, even if it still had a hex head.

No mention from the original poster if he still needs that pic...

 

Aside from the awol screws... I need a rearview mirror button as well...anyone??
Bill (Thanx, BTW)

 

Rearview Mirro Button??? What is that?

John

 

Its the little metal button that attaches to the windshield so you can screw the mirror onto the windshield.

You can buy a new button at Autozone, Napa, or any other parts store.

Just don't put it on upside down!!! That glue they give you is strong enough that after only 30 seconds it will break the glass if you pry it off.

 

I forgot to mention this before... I learned the hard way that the Al piece chaffs the ignition wires. A little convoluted tubing fixed that though.

 

The al cover uses a button head torx screw beveled on the bottom side of the head.. I have some factory covers and screws laying around ..


EDIT I looked at the screws when I got home and the ones for the AL cover are a panhead type torx with a flat bottom instead of a beveled bottom...

 

The aluminum plenum extension has smaller counter bores than the plastic extension hence the different screws.

Also If anyone is interested a have the GM screws for the plastic extension that I would like to trade for the screws for the aluminum extension.

 

I tried a Universal fit, damn thing's square...won't work on GM...hehe
I can try Napa I suppose. I have the 'repair kit with glue a prep supplies...but, sadly, no replacement button. The button did get lost while the car was trailored due to fuel pump 'death'
If you have extra plenum screws, send 'em my way!
Thanx

 

I had taken it off and back on again to do the thermistat, which was a major pain as well, but the screws for the plenum may be at my folks...or were...and gone now. I also don't know where the dome/scoop backplate is but I think I still have it somewhere. Is it best I put it on even if I prefer the look of the hood with a honest-to-g*d opening? I was always curious as to why block the hood scoop... Shaker scoops face backwards and I assumed they were open.

Thanks and sorry I missed that, hurry ya'know
BILL