Intake manifold options
Thread Starter
Instructor
Joined: Aug 2008
Posts: 110
Likes: 0
From: Le Roy NY
Intake manifold options
I've got a GM 290 HP crate motor in my 1980 that's been equipped with dual exhaust, hugger headers, and an RV cam. The stock Rochester Q-jet is still there, along with the 14057055 intake manifold. My question is whether the manifold is a bottle-neck in engine performance. I've read that this is a 305 manifold, but have also seen some good comments about it. The letters "CEM" are cast into the manifold below the part number. I had the manifold off a few years back, and remember it being aluminum.
Is there a better manifold (if needed) available with the same height? It would have to fit under the stock hood.
Is there a better manifold (if needed) available with the same height? It would have to fit under the stock hood.
Melting Slicks
Joined: Mar 2007
Posts: 2,100
Likes: 12
From: Frederick Maryland
About the only aftermarket intake that will fit with no issues is the Edelbrock Performer. There are a few others but you have to be a bit creative with drop air cleaners for hood clearance.
The Performer is likely a better intake but maybe not enough to make any appreciable difference. That's assuming the intake is the only change you would make. To really show a difference would require cam, head work, etc.
The Performer is likely a better intake but maybe not enough to make any appreciable difference. That's assuming the intake is the only change you would make. To really show a difference would require cam, head work, etc.
What he said!
Drifting
Joined: Aug 2008
Posts: 1,381
Likes: 11
I agree. Unless you are going to race this car a lot, keep the factory intake. It makes better low speed power than most of aftermarket stuff.
On the fitment question, the Weiand 8004 fits under the hood with no problems. It is a dual plane and is slightly larger in all areas than your stock piece so it produces a little more power above 4,500 rpm, but retains the good low rpm torque. I have one on my '79 and it works great. It's available without EGR and also accepts both spreadbore and square flange carbs - so that's a bonus if you like to try different carbs (i do) and it looks enough like the stock intake you could paint it and most would never know it wasn't the stock cast iron unit.
On the fitment question, the Weiand 8004 fits under the hood with no problems. It is a dual plane and is slightly larger in all areas than your stock piece so it produces a little more power above 4,500 rpm, but retains the good low rpm torque. I have one on my '79 and it works great. It's available without EGR and also accepts both spreadbore and square flange carbs - so that's a bonus if you like to try different carbs (i do) and it looks enough like the stock intake you could paint it and most would never know it wasn't the stock cast iron unit.
Drifting
Joined: Sep 2006
Posts: 1,259
Likes: 2
From: MS
power than an RV cam and now the cam will be killing your top end more than the intake.
That Weiand sounds good. What happened to the stock cam?
