Intake Manifold

**B-Rad-G** · 01-22-2006, 09:59 AM

Hey, I have a 91 Chevy 1500 with a 305 V8 5.0L. I was wondering what intake manifold would suit my engine. I was wondering if dual plane was better than single?? It wouldn't matter if it fits my TBI because Holley make an adapter plate that allows me to use the TBI on any manifold that a 4 barrel Holley carb will fit on. So basically all it has to do is fit my engine and I can adapt it to fit the TBI. I was looking into the Edelbrock Performer series but not sure if I need the EGR or not. What exactly does EGR mean?? Let me know what you guys think, thanks.

**fastredgmc** · 01-22-2006, 05:33 PM

You do know that edelbrock makes a TBI intake right?

**B-Rad-G** · 01-22-2006, 09:19 PM

Yeah but I read that most TBI intakes are not very good and the Holley TBI has a 2" bore.

**chevyz71man** · 01-22-2006, 10:56 PM

The holley proinjection tbi intake has 2" holes already drilling in it..

**loquito** · 01-23-2006, 08:27 AM

one of my buddys said that you can just port and polish and it works the same as if you would buy a new upgraded one. Not only that but is way much cheeper.

**oldred95** · 01-23-2006, 04:19 PM

Originally Posted by chevyz71man

The holley proinjection tbi intake has 2" holes already drilling in it..

Its 2 inch bored, has EGR provisions (takes a different EGR valve though), is dual plane with huge plenums compared to stock, high rise (its about an inchor maybe a little more taller then stock), and that being givin it makes a lot more power all the way around. When you put your foot into it, it will go, no more dieing from lack of air at top end, it just keeps pulling. I love mine. Down side is its not a direct bolt on, it takes some modifying here and there.

**B-Rad-G** · 01-23-2006, 05:06 PM

Could somebody explain to me what the EGR valve is? Also, if i were going to get a Performer series, which would work on my 91 305? I will be using the adapter for the TBI. Thanks

**oldredtruck** · 01-23-2006, 05:46 PM

E-G-R stands for Exhaust Gas Recirculation... a small amount of the blow by from the crankcase gets re-routed back into the intake flow to be burnt again... part of the emissions system ... yes you need it...
as for intake... dual plane on the little 305/auto tranny...

**scooterboi21** · 01-23-2006, 06:40 PM

Originally Posted by oldred95

Its 2 inch bored, has EGR provisions (takes a different EGR valve though), is dual plane with huge plenums compared to stock, high rise (its about an inchor maybe a little more taller then stock), and that being givin it makes a lot more power all the way around. When you put your foot into it, it will go, no more dieing from lack of air at top end, it just keeps pulling. I love mine. Down side is its not a direct bolt on, it takes some modifying here and there.

What modifications did you have to make to the manifold?

**Fast305** · 01-23-2006, 07:19 PM

You will be MUCH happier with the Edelbrock and a stock sized TBI on a 305. It just doesn't need anymore than the 490 CFM that the stock sized TBI w/ Ultimate TBI mods can flow. The performer intake is a good improvement over stock for upper end power. Around town it will feel as if the engine is out of tune though due to less low-end torque. The Holley will feel worse ( Have on on my S10s 305 TBI, but the truck is light, had it on the G20s 355 and it was a pig on the bottem)

**mbest** · 01-23-2006, 07:27 PM

By the way, since we're talking about the projection manifold, does it run OK with the smaller bore sized TBI ? Or should you port match the spacer (stock size on top end gradually enlarge to 2" bore on manifold end? Thanks, Matt

**oldred95** · 01-23-2006, 08:17 PM

Stock bore TBI works fine on the 2 inch bore intake.

I never lost any lowend with the intake. I have the worlds worst configuration for lowend power too but I still have a decent amount of it. I love the intake but mine is a 350. Like fast 305 said, a 305 may hate it.