I'm planning on using vortec heads on the 350 I'm preparing to build, there aren't too many vortec intakes available, especially at reasonable prices. I know I can use a carb intake with an adapter/spacer but I'm worried about the fitment under my hood. I had planned on using an Edelbrock Performer RPM intake with a 1 inch spacer/adaptor. Does anyone know if that will fit or an intake that will definitly fit under my stock Firebird hood?

 

My first choice would be the Edelbrock Vortec Carb intake for 2 barrel. with an adapter plate. will it fit? Note sure. need to go to site and compare the height of each.

My second chice would be a Weiand Accelleraror low profile single plane for carb/adapter plate. Yes a single plane. And I am confident it will fit.

You will need to tune.

 

The tune was a given, its a full heads/cam/intake swap. I'm not quite sure if that Edelbrock would fit because my stock TBI set up with a 3' drop base air cleaner is already touching my hood insulation... but I'll take some measurements.

What's the downside to using a single plane over a dual plane?

 

I will say with a carb there is a definate downside. But EFI tends to overscome that. I believe it has to do with velocity of the air flow from intake to combustion chamber. Dual plane helps that for carb. EFI may not be as important. I ran the weiand SP years back and with a 210/214@114 LSA I had zero TQ loss under 3500 rpms. I went to a Holley Projection(dual plane) afterward and it may have been a mistake. I increase cam size at same time.

 

Do you think I'd be better off just shelling out the extra cash and converting the car to TPI?

 

I went brain dead. I dont think Weiand makes a "low profife" for Vortec but I am sure others make a vortec single plane. Again may not fit.

Heck no not TPI! Port fuel yes but not TPI. I wish I had done so at my last EFI conversion. If I had done so I would most likely have a Holley single plane port fuel intake with accufab 4 barrel sequential TB. Run by EBL.

I recall checking measurment on Holley vs Edel SP and Holley was shorter.

 

I'll have to look around some more. I might just pay the extra money and get the GMPP since its made for TBI and should fit.

 

I bought the GMPP TBI Intake when I swapped in a pair of 059 Vortec's. It's a bit more expensive but retains EGR (if you need to pass emissions). You'll need to modify your Throttle/TV/Cruise control bracket to clear one of the intake bolts.

I have no regrets with buying the intake..plus it's aluminum.


Also, the EGR provisions are different on the GMPP. You'll need to tap n' weld an egr bung to the driverside header and buy the specific EGR tube and weld-in parts. I just capped off the EGR and tuned it out (no emissions in NE)

 

Not to worried about EGR. How is the RPM range on it?

 

Well, to be honest I'm not all technical with how I feel about the intake. Throttle response was vastly improved, the car pulled better across all rpm's, noticed most improvement around 1750-2500 rpms.

I don't try to drive like I'm drag racing to the grocery store...I just like a bit of get up and go.. Another piece of experience would be that I could fit the intake, an inch spacer, the tbi, a larger pod spacer and the OEM air intake without messing with the hood. I did notice that the stock tune couldn't handle the upgrades has I had some lean pop upon cold morning start

 

Well that's all good to know. Thanks. I believe the RS hood has a bit more clearance than the Firebied hood does, can anyone confirm? The price of that intake is still a big killer but its certainly cheaper than converting to TPI

 

Did you ever get a surefire answer on this one? I'm basically in the same boat as you.

I'm pretty sure the camaro hood has more clearance than the firebird hood does. In regards to TBI setups, I'm not sure how much of a difference it is, but I do remember reading something on holley stealth ram intakes about how they'll clear the camaro hood, but some cutting of the hood webbing/bracing is require to get it to fit under a stock bird hood.

I just bought the GMPP TBI intake manifold recently. Hopefully sooner than later, I'll get a chance to compare it to the stock manifold's height, but it may not happen immediately. Still kinda gathering up parts/eyeballing a workspace to do my swap. I went w/it mainly because of emissions testing in my area, but I'm also hoping it's shorter than a carb manifold w/an adapter plate

 

I never got a straight answer. I was thinking just going HSR since the RPM range is larger, should give me more torque, and the price is pretty similar. The Camaro hood does have more clearance.

Please let me know how that intake works out for you though, I have a 91 RS that needs something soon.

 

Will do! When I get to it at least, lol. If you go port fuel, definitely go HSR/Superrram/Mini-ram, etc. I originally thought of going TPI, until I learned more about how to make the TBI work well, and saw the cost of the TPI parts . If you decide to stay with TBI, you can always bore out the intake manifold inlets and the throttle body to get a nice power increase. Upgrading the ECM w/something like EBL Flash is a must though.

Not sure, but I think you need a TPI wiring harness for the HSR. Someone else will chime in on this though.

 

I would take a look at the Professional Products line of Vortec specific manifolds. Much lower in cost and I never saw negative feedback. Possibly the single plane can be machined off at top mounting surface. My Weiand Acell SP was machined about .375 to .500 to allow more clearance. I am sure they have a standard vortec dual plane to consider as well along with a mount plate. Mounting plates come in .375 and .50 inch. I bought a .375 with 2.0 inch bore from Howell.

 

I'm a huge fan of the Efelbrock Vortex Carb.