Intake manifold issue.

[purebred]

I have a 350 performance engine in my 65. When I bought it, it had a Holley 650 double pumper carb on it. I recently put a Edelbrock 600 cfm performer carb on it to try and get a couple more gallons out of it. I have a Weiand single plane intake, My question is should I go ahead and pay for a new performer dual plane manifold or am I just throwing money away? All in all it runs pretty good now butidle is not always smooth until it realy warms up, I have heard that single planes verses dual are a little different, should I pay the 150.00 or just stick with the Weiand? any input is greatly appreciated. Thanks

[gofastnut]

I have run both and the dual planes seem to have better manners at and off idle. They seem to be a little more daily driver friendly.
And I'm pretty sure you can pick up a good used for less than the $150. How bout it members, anybody willing to part with one for a good cause?

[61_FL_Apache]

I would think there would be much difference.

[purebred]

I put a vacum gauge on it and it seems to have the right amount of vacum. What would the differences be? Any gas mileage change or is it just a torque verses rpm thing?

[11echo]

It depends on what you want you engine to do! "IF" you want a drag racing screamer then a single plane is the way to go! "IF" with want a "burn across the intersection" engine then a dual plane is the right choice. It's a matter of physics ...it takes longer for a volume of air/gas to reach it's peak going down a "big hole" then it does a "small hole" (i.e. dual plane) ...SO bottom line is dual plane is "quicker", but single plane is "faster"! ... Vacuum reading won't change between manifolds at idle.

[T Smith]

The single plane you have, being a performance manifold, doesn't have a heat crossover which is the reason it has to warm up a bit. A good dual plane will have better low end torque and street performance, and most likely have a heat crossover unless you go with the RPM model.

[purebred]

I am going to bite the bullit and get a new performer 2701 manifold to go with my 600 cfm carb.

[Corts60]

I agree with above. Dual plane for torque, single plane for top end.

[awbrown]

If you really want good milage I would find a Quadrajet with an electric choke , jet the primaries up 3 or 4 numbers and like the others said get a manifold with an exhaust crossover,the performer with the q jet pattern would be a winner.... 2101 ..........

[gofastnut]

Originally Posted by awbrown

if you really want good milage i would find a quadrajet with an electric choke , jet the primaries up 3 or 4 numbers and like the others said get a manifold with an exhaust crossover,the performer with the q jet pattern would be a winner.... 2101 ..........

x2

[markeb01]

If you want to save gas grab a strip kit and start leaning that new carb out. It took me quite a few changes and road tests to dial mine in. Edelbrock carbs are setup very rich from the factory.

[awbrown]

I experimented with jetting for a year as I drove my 73 c10 180 miles to tech school ,tried a few different carbs and went from 8 mpg with an old 4jet rochester , to 12 miles per gallon with a qjet jetted with 74's on the primaries it always felt dead jetted at 68 so we kept bumping it up , got more responsive and better milage ..

[Captainfab]

I agree that dual plane intake will be better for a street driven engine. Here is a used one at a good prive, if you don't mind doing a little cleaning.

http://www.67-72chevytrucks.com/vboa...d.php?t=511076

If you do decide to go new, consider a Performer EPS. It is basically a little more refined Performer, to squeeze just a little more TQ and HP. Plus you won't need the adapter plate to bolt a square bore carb on it, since it has a square bore carb pad.

http://www.summitracing.com/parts/EDL-2701/

[purebred]

Markeb01 , if you don't mind me asking what did you finnaly do (Jet wise) to dial your edelbrock in? Jets and metering rods, would appreciate the info, thanks

[blackedoutharley]

Originally Posted by Captainfab

If you do decide to go new, consider a Performer EPS. It is basically a little more refined Performer, to squeeze just a little more TQ and HP. Plus you won't need the adapter plate to bolt a square bore carb on it, since it has a square bore carb pad.

http://www.summitracing.com/parts/EDL-2701/

^^^^^ !!!!!!!!

Don't waste money buying a new standard Performer manifold. The EPS is a great piece for the money and is a square bore so no adapters.

[Captainfab]

I might add that the Performer EPS can also be had with the front oil fill tube, if that is something that interests you.