yes thanks need sizes, i do own a drill press...

let me see if i got this straight, pun intended,

1/ mock it up without the base plate, ( i'm assuming the plenum has the bolt holes that are all the way through them from the factory, this serves as a plilot hole of sorts)

2/ leaving the 4 inner most troublesome bolts out, flip the unit over with the runners up, then from that position drill down ( with a hand drill and sharp bit), with a bit size just large enough to remove the threads from the plenum and increase the size of the runner holes to match, all this with one fell swoop. ( you will give me the size?)

3/ now take the runners off the plenum and increase the size of the hole on the plenum 1 size larger than the previously used bit, and clean it up with a chamfering bit( i'm assuming, this gives wiggle room, when fitting the box for final assembly.)
by positioning the box with the original drill bit to center, we are eliminating any chance or shifting and cause a misalignment issue.( do this with all 4 holes)

4/ Using a tap, that matched the size of the hole drilled to the runners, create clean threads on the runners, repeat 4 times and screw in studs to these holes after cleanup, ( loctite red?)

5/ if i sit back and look, i will see 4 studs( how long?) sticking out from the middle of the runners were it meets the plenum, not the manifold, duh...

6/ use appropriate nut to secure box to runners paying attention to the quality of the fasteners, safety wireing is suggested, but not mandatory? again ( locktite red?)

7/ use profanity as required

and to see if i got this, there are 3 ways to tackle this and in the order of assembley speed, 1/while this is the most speed effective manner to provide access in sealing this area of the plenum to runner interface, the down side is the protrusions interfering with airflow, including a minimal chance of the engine swollowing loose nuts, 2/ studding the plenum in the same area (Where the studs are pointing downward), instead of the runners (pointing up) eliminates the aforementioned disadvantages,however redirects access to the bottom on the box, where interference from the base plate slows attachment, while still improving on the 3/ original bolt only configuration.

 

All I did was run a 5/16'' tap through the existing holes in runner flanges and put a back up nut on the stud where it exited the runner flange. The plenum already has a screw hole, which makes a nice pilot when drilling the plenum to allow the stud to slip through.

 

You have it.

Edited - Agent 86 posted what he actually did. So it sounds like you only have to drill out the plenums holes to accept the studs. Just take your time when you tap the runners, aluminum wants to gun up your tap.

I would not want to chance having a nut back off in the plenum and be sucked down the intake. I would not trust locktite since you are in the engine compartment and have a heat source that is on and off again. The locktite could fail, might not but could. I would safety wire it or use very small cotter pins. This means you have to drill a small hole in the studs. Tape off runner holes like Agent 86 has in his picture to prevent anything from dropping into the intake.

And you are right, it looks like the very quickest way to install the inside runner to plenum fasteners is to run studs into the plenum with nuts and safety wire per Agent 86. Next fastest is studs in the plenum that stick out below the runners. Last would be stock screws from runner to plenum.

John

 

i didn't know that the runners has threads that accepts 1/2-28 size, since it does, it could hold the bolts at the runner just before it penetrates into the plenum, right? if not threaded i could shim it some way to hold the bolt like aluminum foil ( mickey mouse man)

this would be true with all plenum to runner bolts correct?

what if were to cut slots on the tips of 4 of the bolts ( i would'nt know how to do it dremel and a vise?) designated for inner runner duty, and using a jeweler's screwdriver or a any flat tip screwdriver that fits within the plenum bolt holes ( i believe your saying their 1/4 inch) and turn these bolt counter-clockwise to start the tightening sequence (times 4), and reach below with the right size wrench ( if at all possible) to snug it up?

then there is no way anything can fall in the engine, while enableing the installer to manipulate these fastener from the top vs. the bottom. the best of both worlds?

what do you think?

 

Don't forget about the time required to r&r the lid with all those button heads if you go with some internal fasteners for the plenum. With the studded plenum, I just leave the lid on.

I think this saves some time and also reduces the risk of dropping something down the runners when the lid is off.

I've had my plenum off 2-3 times now since the initial install. I don't find it to be too difficult, but can be a little tricky spinning the kep-nuts on from below with a finger tip, but it doesn't require much time to do so.

How often to you intend to pull it apart?

 

OK pics might help you see what I'm talking about.




As for the remaining runner to plenum bolts, cut a slot in the tips so you can use a flat head screw driver (inside plenum) and pull them into position, for tightening with a wrench.

Having the studs with back up nuts, turned out to be a good idea. My runner flanges had a bit of a bow (maybe due to me powder coating them in the oven). I was able to apply a lot of torque to the stud nuts and pull the flange flat and tight to the gasket.

 

wouldn't just cutting slots on all the bolts do the trick?

btw, does any of the fasteners require washers, lock or otherwise?
are they all allen heads? what material are they made of? does it have to be some exotic material or just zinc coated is fine?can i substitute some of these for black or chrome,

these are all allen heads right? will the stock plenum to maifold torx bolts work? t think the mainifold is interchangable with thew stock manifold spec to spec in demiensions right?
cause i'd like to go get them before the unit comes

 

i bought m8x25 1.25mm pitch for the socket head bolts same for the 30mm lenght hope its right.

 

there are 6 m8x25mm and instead of m8x30, they could go to 35mm, but since i have the 30's i'll stay with 'em, only one could use a little more thread.

and i'm studing all of the plenum bolts no drilling, 1 the inch studs are perfect length, not too long not too short!