Am thinking about updating my factory intake manifold to a performer rpm one. As am looking on summit racing at the different options what are the difference between them. One say dual plan and the other one say single. This is for a 350 rocket motor.

 

What have you done to the rest of the motor? What do you want to get out of this swap?

Despite what you may read in magazines, the engine needs to have all components matched for best performance. Are you running single or dual exhaust? What carb? Headers or manifolds? What compression ratio? What cam?

I would strongly recommend a dual plane for the street, especially on a nearly stock engine. The Performer RPM is a good choice, but don't expect a dramatic increase in performance.

 

Joe - I bought my car several years ago and was told the guy that owned the car was building it for racing "whatever that means". The car have a mild cam, dual exhaust, q-jet carb 4bbl. I have never taken off the valve covers yet to see if the lifters has been replaced or not.

 

Yeah, that means about as much as "3/4 race cam"...

The RPM is a reasonable place to start.

 

Joe, am looking at two different one's on summit and trying to decipher the difference if any. One says "performer rpm" and one says just "performer" is there truly something different between the two?

 

Yes, they are completely different intakes tuned for different operating ranges. Edelbrock's web page describes the different design RPM ranges and has photos that show the runner differences. The RPM has a taller carb mounting surface and larger, more direct runners tuned for higher RPM performance. The Performer is only a marginal improvement over stock. I would only consider the Performer for a small motor like a 307 or a heavy car like a Delta 88. The RPM will be a better choice for your application.

 

Thank you Joe for your responses and knowledge.

 

Summits catalog descriptions arent always correct. Both the RPM and the standard Performer are dual plane manifolds,but the Performer is for stock level rpms and the RPM is for higher performance

 

Be aware that the Performer RPM does not have a provision for the factory hot air choke, so you would need to convert to an electric choke. That is a very simple modification - a basic install just needs an electric choke coil and a length of wire to a 12 Volt switched power source.

 

Block off the heat riser either in the heads or in the intake(preferred). Weld in the plugs. Adapt the Qjet to an electric choke. Invest in a new OEM thermostat housing and use a dab of anti-seize on stainless bolts, if yours is questionable. Glue the gasket to the housing with spray gasket sealer and apply a small amount of clear RTV to the intake side. Torque lightly. FYI you wont find lifters under the rocker covers.
Do not use the rubber front and rear block to intake runner seals. Rather run a bead of The Right Stuff (Gray RTV) in place of the OEM seals.
Optimize the ignition timing curves as well as the Air Fule mix.
Retorque the intake after about 2-500 miles.

 

I'm going to disagree with this. On a street driven car in Oregon, you'll never feel the difference and cold weather driveability will suffer. Certainly if you plan to spend the money on custom porting the heads, then definitely fill the ports in the heads - more to improve exhaust flow than to block carb heat. Unless you plan to fine tune carb jetting on a dyno or with back-to-back passes at the drag strip, blocking the crossover is a waste of time on a street driven car.

If you DO want to block the crossover, I'll pass on a trick from Hot Rod (or maybe Car Craft) from the 1960s. Wad up small ***** of aluminum foil and tamp them into the crossover on the intake. All this costs is one roll of foil, and you can dig them out if you decide you don't want them.

 

I am liking my non filled heads #6 heads much better than filled #6 heads. They ran terrible in cold weather. The 2711 non EGR version of the Performer also doesn't have the hot air choke provision. I had a 3711 Performer lying around, I added a 1" open aluminum spacer. I open it up to better match the intake opening. My combo is borderline, maybe I should have just grabbed the RPM off the shelf instead. The RPM is 2" taller FYI.

 

Joe we know and respect your opinion but I don't have any drivability issues as I tuned it in pretty good. I always let it warm up for a while before taking it out. If you wanted to get in and drive right away then yes it would be an annoyance, but you'd have a similar annoyance if you didn't let the electric choke pull off for a minute or three. Remember I have the divorced choke and the OEM iron intake. The electric choke would solve this. Mine is a cold-blooded beast when the ambients below 35*F But it doesn't see the road at that point so its a non-issue.
For me, I had a hot start problem that would not go away. This was the last step and the only solution I found. It simply keeps the heat off the carb and the paint doesn't burn off the iron intake. win win.
Aluminum will dissipate the heat better, but why not remove the heat source and prevent the discoloration. The car will run much better without the added heat, especially when under hood temps get high. Denser changes are always favorable with the Olds school engines, just one old man's opinion on what I believe to be a worthy modification to a non-daily driver.