I am going to be building a 383 stroker with all aftermarket TPI on it to replace the V6 in my car. I am going to use L31 vortec heads with the TPI vortec baseplate, both from SDPC. I am also going to us the intake runners from SLP. I was wondering if any aftermarket companies make an upper plenum. I have searched all over SLP and can't find one. Thanks in advance.

 

Accel makes the Superram, but you have to use their runners, also. It's a little pricey. And if you go that route, you should get the Accel base manifold also. You can just port your stock one and if your getting SLP runners, siamese the runner openings to match the SLP runners. That is what I did. I love it. I also have the Accel base manifold.

 

TPIS ports plenums for about 100 bucks. Whether you do it yourself or buy one, a ported upper in absolutley necessary if you're going to breathe a 383 through long tube runners...

 

But... does any aftermarket company make a nice upper plenum or am I stuck using a stock ported one?

 

ive seen an aftermarket plastic one, but it has no benefit over the stock one, and i dont think its made anymore.

 

As far as I have ever seen you will be stuck with the stock upper plenum. Not to despair though, if you are handy with a die grinder, there is tons of info around here on porting an upper. Also with the Vortec heads, you cannot use the Accel lower intake without modification... I would just port the SDPC lower to make up for it!!

You know the Holley Stealth Ram intake sells for about $600. With a 383, believe me, they like to breath. For the money you are going to spend on the runners and lower intake, I bet you could have the HSR. Just need to find out if it bolts to the Vortec heads. Just a thought.

 

That's the problem the stealth ram does not fit on the vortec heads.

 

THat's true...

 

Accel makes a plenum, but it's identical to the stock one. There is no reason to buy anything other than the stock plenum anyway. There are no gains to be had that you can't do with a stock one and a die grinder.

 

Since you're a Bay Area bro, I thought I would offer my .02.....


Your combo will never pass smog test, unless you have someone you're going to payoff.

The L31's do not have an exhaust crossover port for EGR, means the only way to get EGR (to the manifold of your choice) is to run it like the Vettes do, off the exhaust manifolds...unfortunately, NO_ONE offers a CARB approved kit to do this.

Yes, kits are available, but not CARB approved.

Good luck, my opinion is for you to rethink your engine build.

 

I have seen a few cars here in California pass smog legally with the EGR set-up like the Vette.... As long as it works correctly, you should have no problems.

 

Maybe "not a problem", but...

My last smog check in Fremont took 3 hours, 15 minutes for the test, and another 2:45 for SLP to fax the station a copy of sticker for my headers.

I did have the sticker attached, but one of the EDO numbers was worn enough it could not be read correctly.

I'd guess it matters who's doing the smog test.

I would still rather error on the side of caution and do things that are correct, rather than assume it'll be okay.

There's such a fine these days for the smog guys who let things slide, it's always best to ask first, before you do anything.

If I recall, there is a Ca. BAR waebsite, list numers, etc, you can call to check things out.

Also a good idea to go to the place you intend to get it smogged, and ask "What if".

I even "flunked" tghe smog on my '78 for having the aircleaner lid flipped upside down in Modesto.

I had to leave the station, flip it over, then come back for another test. The guy wouldn't do it there because "he could be caught tampering" with the emissions system.

Grrrrrr.

 

i hope jersey doesnt get this bad... i have a sticker in under the hood that says that my MSD coil is all good in cali...

 

Damn, I am glad I don't have to worry about that nonsense with emissions testing. Like cars pollute that much anyway.

 

I am not planning on making my swap smog legal. i don't care about that. I am going to put all of the electrical and plumbing on quick disconnect and every two years when I have to get my car smogged, swap my 2.8 back in.

 

That seems like a lot of work!!

 

I dont think it will be too bad. I will take the tranny and motor out as one unit, and put my other tranny and motor in as one unit. The hook everytihng up. I hope to be able to do it in one long weekend, get it smogged, and then do it again in another long weekend.

 

I know Cali has harsh testing standards so I guess that is your way to have the best of both worlds. What about your exhaust though? That might be a bitch to change. Just a thought.

 

I was thinking of just using some hangers that will I can unbolt my V8 exhaust and then just bolt my V6 exhaust right back up to the same spots. To me it really doesn't seem that bad, but I have been thinking and planning about this swap for a while now. When I get there, I will take pictures of everything that is going on and post them up here on thirdgen for all of you other guys to see.

 

Good ideas. I hope it all works out for you.