[DogMeister]

I'm getting ready to put my "new" '67 GTO together. The motor is a 461 stroker with #45 small valve heads, 10:1 compression, a Melling SPC-5 cam 4 degrees advanced, flat hydraulic lifters and a QJet. I've been running this engine in the "old" car for 5 years. I built it for torque, it does 450 ft-lb and 260hp at the rear wheels and runs GREAT.

The intake is a cast iron egr from a '75 who knows what, it was on the car when I bought it 17 years ago. I have a Performer RPM manifold just sitting there that I could use. I'm not really well-versed on what it'll do versus the stock manifold. I assume a little less low-end torque and a little more top end hp? I could live with both, plus it looks cool. My other thought (again, more for cool than performance) is the '70-71 aluminum HO or Ram Air style manifold without the crossover. There's just enough hood clearance for the RPM.

It's a show car/cruiser will never see the drag strip except for some fun. I do put my foot into it frequently. Would be interested in everyone's opinions on the two manifolds.

[HoneyHush]

If it were mine I would definitely put the RPM on it. It would look better, be a little lighter, and make more power.

[i82much]

I'm no expert, but I don't think you've got the cam or head flow to take advantage of the RPM. If you wanted to port the heads, run a bigger cam, headers, go that route it would make sense, but otherwise I wouldn't mess with it. Honestly, with these cars, when they are running good and you are happy with them, go cut the grass or drink a beer and don't try your luck!

[leeklm]

The RPM should work well. Hood clearance would be tight, so may need a drop type filter base and no spacer!

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[Steve C.]

Take note of the Performer RPM port exit dimension compared to the factory iron heads. The RPM intake as cast is about 2.060" tall.


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[steve25]

Even with stock BIG valve D port heads you would not see a improvement with the rpm Performer unless the motor is built to make peak HP above 5500 rpm which yours is not not!
If you want to drop off some nose weight then sell or trade the perfromer rpm for a basic perfromer.

[NeighborsComplaint]

Thrown on the RPM. It has the look even if you don't gain any performance. I wouldn't expect you would lose anything performance-wise. If your intake has the "D" shaped emissions era secondaries (limits secondary plate opening), you will gain performance over the stock intake. With the small valve heads, you will have very strong low to mid-range performance plus you get the cruise-night look from a piece that is just sitting in your garage.

[Formulabruce]

Originally Posted by i82much

I'm no expert, but I don't think you've got the cam or head flow to take advantage of the RPM. If you wanted to port the heads, run a bigger cam, headers, go that route it would make sense, but otherwise I wouldn't mess with it. Honestly, with these cars, when they are running good and you are happy with them, go cut the grass or drink a beer and don't try your luck!

Exactly! The RPM is for .. more RPMs, NOT Torque
a regular performer WILL make a difference vs a EGR intake... ( 348 bucks now, UGH)
Pontiac had a 265 hp 400 in 1970 with 400 Torque at 2400 RPM.....
Small valve heads..... 2bbl !
Enjoy the Torque!

[tom s]

I have a NOS performer for sale on this site.Tom

[Kenth]

1975 Pontiac Qjet intake is as good as any year Pontiac Qjet intakes.
Performer may be adequat for a 350 and RPM if you plan for use above 500 hp.
Why mess with success?

[leeklm]

My favorite part of the aluminum option is bending over the fender to remove and install vs cast iron!

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[RocktimusPryme]

Most dyno testing Ive seen with an RPM (across most engine families) is that it provides a lot of piece of mind. Even in situations where it doesn't gain any power significant power over a stock intake, or a base performer, it also doesn't give any up. I feel like in almost any street car situation, you can use an RPM and feel like you didn't make a bad choice.


IMHO hood clearance aside. There is no situation where I use a regular performer over an RPM. You might say, "All you need is the Performer". Which may be true, but the RPM is going to make the same power while giving room to grow.

[ZeGermanHam]

Originally Posted by RocktimusPryme

Most dyno testing Ive seen with an RPM (across most engine families) is that it provides a lot of piece of mind. Even in situations where it doesn't gain any power significant power over a stock intake, or a base performer, it also doesn't give any up. I feel like in almost any street car situation, you can use an RPM and feel like you didn't make a bad choice.


IMHO hood clearance aside. There is no situation where I use a regular performer over an RPM. You might say, "All you need is the Performer". Which may be true, but the RPM is going to make the same power while giving room to grow.

I agree with all of this, and it is consistent with intake manifold dyno shootouts I've seen online. Even on a "low performance" engine, the Performer RPM does not hurt anything and in many if not most cases there are gains. It also seems to be pretty consistently reported that the only advantage the regular Performer intake has over a nice factory iron intake is weight, not performance.

So yeah, if you've got a Performer RPM laying around, throw it on.

[Matt Meaney]

Originally Posted by i82much

I'm no expert, but I don't think you've got the cam or head flow to take advantage of the RPM. If you wanted to port the heads, run a bigger cam, headers, go that route it would make sense, but otherwise I wouldn't mess with it. Honestly, with these cars, when they are running good and you are happy with them, go cut the grass or drink a beer and don't try your luck!

obviously, you're not of the camp, "if it ain't broke, mess with it 'till it is"

the only thing i have to say about the performer rpm is, my new one didn't fit. it needed to be milled .060 each side. ( the thickness of the gasket)

[6T5 Cat]

Originally Posted by Matt Meaney

obviously, you're not of the camp, "if it ain't broke, mess with it 'till it is"

the only thing i have to say about the performer rpm is, my new one didn't fit. it needed to be milled .060 each side. ( the thickness of the gasket)

Had the same issue about 12 years ago when I bought a new RPM intake and a set of new E heads directly from Edlebrock. The intake didn't fit, it had to be milled .060 and the new heads had three different size rocker arm studs in them.

[jamaca85]

i have a 79 firebird that i wanted to put an rpm on has the aluminum heads on it . but the hood clearance was an issue...i went with a P4B the one for a square bore carb cause i had a holley. idles great and has lots of power no issues. Im sure theres a difference between the 3 choices but a stock , performer and a P4B are small on the street and just noticable on the dragstrip when you see the et and mph. just dont do an open plenium like a hurricane, torker or street dominator.

[NeighborsComplaint]

Results of Jim Hand's 1/4 mile testing of multiple intakes on a well dialed in Street455.

Stock cast iron intake with notched divider is the control group. Interesting that the Torker II outperformed the Performer RPM though this is splitting hairs on a street driven car. Only the OG Torker and Street Dominator were significantly slower.

* Pontiac Aluminum HO Lost .08 sec. and .4 MPH
* Edelbrock Performer No change in ET or MPH
* Edelbrock Performer RPM Lost .05 sec. and .5 MPH
* Edelbrock Torquer II Lost .0l sec. and .1 MPH
* Edelbrock Torquer Lost .29 sec. and 2.85 MPH
* Holley Street Dominator Lost .25 sec. and 1.9 MPH

[i82much]

Originally Posted by Matt Meaney

obviously, you're not of the camp, "if it ain't broke, mess with it 'till it is"

the only thing i have to say about the performer rpm is, my new one didn't fit. it needed to be milled .060 each side. ( the thickness of the gasket)

i was in that camp for a long time! now my theory is, during driving season, i don’t touch anything unless it breaks!

[STEELCITYFIREBIRD]

Depending on how tight the hood clearance, you will have issues if the air cleaner lid is too close to the top of the air horn.
Do a search online, (https://www.pontiacdiy.com/pontiac-v...ormance-guide/) you will find the restricted secondary later intakes give up nothing at your rpm range.
Also when checking for hood clearance, take into account the AF stud. It will be above the lid. And if you use a lid with a recessed area for the wingnut, lid will be that much closer to the air horn/choke tower.

Myself, I'd stay with what you have and sell off the RPM for some higher ratio rockers, if your on stamped steel 1.5's now ...and heads/springs can accommodate the extra lift. The cam, to me, is pretty small for a 10:1 461. Your torque # should be over 500 with that displacement.

If it goes too fast in the 1/4, add a throttle stop or limit secondaries as needed.

HTH

[Stripes]

We dynoed the rpm and the factory intake after engine assembly. The 469 with stock e heads, a hyd roller 236/242 @50, and the stock manifold beat it everywhere all the way to 6k. About 15 hp difference. At 500hp, the rpm was worth negative 15 hp against a port matched 73 iron intake.