Interchangeable plenum?

[droid017]

Alright guys, I bought a NA to TT swap, and while I know the chassis is a 96, I have no idea what year the engine is. I know at some point, the plenum changed designs just slightly, and I really need to know how to tell them apart. I want a polished plenum, but I can't really leave my engine apart for a week or more, so I'm planning to just pick up a cheap used plenum, polishing that one, and swaping them out. What should I look for to make sure I get one that will match? Thanks guys!

[droid017]

And while I'm at it, are the valve covers interchangeable?

[Ace2cool]

Valve covers, not sure, since the '96 dropped VTC for emissions purposes. Check to see if you have VTC solenoids on the back of the intake side cams. If you do, it's not a '96 engine, and all '90-'95 valve covers will fit, and I think the plenum as well. I'm not sure of the design difference in the '96 plenum/ valve covers though, so if anyone has any insight, please enlighten us.

[droid017]

I know it's not a '96 since it had the old style injectors. Still not sure about the plenum though. I think the design changed in 93-94 for the n/a and '95 or something in the tt, but I don't know which differences to look for.

[NolimitZ32]

93 for Na 94 for TT, change came with injectors/lower plenum, AFAIK the upper plenum should be the same, never compared them so cant say for certain.

[BigTDogg (MA)]

Upper plenums are the same for fit 90-96. 95 and 96 plenums have tabs on the front for throttle spring covers, and that is the only difference I know of.

[droid017]

Thanks Big Dogg. Side note: I've seen some throttle springs that are black, are these just painted or are they aftermarket?

[BigTDogg (MA)]

Painted, along with the plastic parts.

[droid017]

Hmm that seems like a tricky piece to paint. looks good though.

[BigTDogg (MA)]

Well, yeah. You gotta remove them I had my throttle bodies and plenum powdercoated, so I painted the springs and spacers while everything was apart and at the shop.

[droid017]

With just engine paint? How's that holding up long-term on a moving part?

[BigTDogg (MA)]

I used Rustoleum Satin black on my timing covers, valve covers and throttle springs and spacers. No heat issues, and they move so little they've been fine. Proper degreasing and prep is essential.