GREGGPENN

$100 OBO







Should work on any of the years posted. Also, it has an extra hole tapped for another vacuum accessory, MAP, or SC. Plug included if you don't want to use the extra hole. All vacuum nipple will work the same. Scratch above bolt-hole will not affect seal.

This should match up with a CorvettePlenum set of mega-siamesed runners. Or...can be used with stock runners.

NOTE: Runners are NOT included with this sale.

jeffp1167

Let me know if it hasn't sold by the 20th!

GREGGPENN

BTW, after a PM I received, I should clarify one point. There is a difference between the 89 and 90-91 plenums. The later plenums have one extra threaded hole for the MAP sensor.

With this [89] plenum, you wouldn't even need to drill/tap for a MAP mount. You could use the extra threaded hole. There are no other differences in the 89 vs 90-91 plenums. So, this would be interchangeable.

jeffp1167

Sorry have to pass ... Mine is a 90 and doesn't have all those ports on the side. Think mine has 3 .....

GREGGPENN

Yours has four...I think. Even if it has 3, it'll still work. Just use the plug.

Unless you're looking for NCRS compliance.

GREGGPENN

ttt

slickfx3

if i put these on my car what would it be like comp 280 xfi cam, frankly I like the looks of the stock setup better than the super ram,

do I have to go smaller on the cam as well, you run a stock ported plenum as well don't you?

I decided not to take my car pass 5500 rpm for over a year now, the super ram may be a waste....

I don't think super rams are selling too fast in this economy.

GREGGPENN

When I mega-ported my SLP runners and my plenum (like this one), the whole idea was to create a psuedo superram. Mine's not QUITE as high-revving as a superram. Mine snaps your neck right from idle to 4500rpm. Instantaneous response is over-the-top,,,like a 427 or larger. From 2000-4800rpms it feels like a boosted 383. In those rpms, you only need 2 secs to be well above any speed limit. (And, I might be able to get more up top. Never been on the dyno yet.)

gkrynick22

Damn, if this worked on an 1985 I would be all over it. Good luck with the sale!

GREGGPENN

Sorry, you'd have IAC problems if you tried to mate this to a pre-89 throttle body. But, it will work with any 89-later setup.

Please PM or email me with responses to this forsale thread. Since replies stop showing up (under the "My Recent Topics" search) beyone 1 week. I may not see a reply for quite awhile after your response.

Avoid that problem with a PM or email.

Thx!
gp

yaknow

School me on this, I believe this will work on my '89. What else should I be looking at replacing. I'm thinking at a minimum ported runners and larger throttle body. What other mods would be needed to take advantage of the ported plenuim?

GREGGPENN

This will work on your 89. And, you don't need a larger throttle body. The stock unit is plenty big as-is. (I'm using my stock unit on my 383.)

I'd mate this plenum to fluted TPIS/ASM runners or go all-out with the mega-SLP route (like I did). Note: CorvettePlenum.com does this kind of porting on SLP runners.

If you stick with the stock heads, no other change is necessary (though you could port match the top of your base to the bottom of alternative runners. (Note below)

Without any additional modifications, a tune would not be required. You'd just hit higher values in the MAF table with a higher flowing intake. Stock injectors would still be sufficient. If they are original, I'd replace them just because of their age.

Note: Considering the reputation of SBC intake gaskets, the full recommendation would include pulling your base and redoing the intake gasket. Of course converting to a new, aftermarket main converter (with aftermarket or no front converters) would help your power gains as well.

Here are a couple of pics of what I did with mine....

GREGGPENN

Just to be clear, this porting will work with OEM runners, aftermarket runners (TPIS/ASM/SLP/Edelbrock), fluted/ported runners, or mega-SLP. IOW, No stock or aftermarket runner flange would fail to "cover" this ported plenum.

yaknow

thanks for the lesson, let me get my head around this so I can start making some prudent decisions. Could you e-mail me drjuhl@comcast.net my goal is about 300hp understanisng that plenium, runners and throttle body have to change, and probably headers and exhaust need to be added. I don't want to dig into the cam or pistons and rings is this a reality or false hope?

cv67

For 100 you cant go wrong on that plenum would cost at least that to have it done plus ship 2 ways.
Surpised noones jumped on it yet.

GREGGPENN

Thanks for the bump, Ron!

GREGGPENN

Still for sale.

(If this post is over 1wk old, please email to get my attention.)

Red C4

I'm interested . What would I need to do to fit this to a 1991 L98 ?

GREGGPENN

I'm sorry. I didn't post this thread as closed. The item has been sold.

Tact