Tuned Port fuel injection fits under all stock C3 hoods.

 

24lbs is a BIG weight savings!

 

So, it looks like the manifold on my 69 350/350 is aluminum.
Is it as good as a performer?

 

rpm air gap, 625 demon, with a gm drop base and 2.5in knn

fits like a glove.

 

Fenton tri-power!

(for sale)

 

The 350HP intake is better than a performer manifold. The performer RPM is close. Joe

 

I understand this is a very old thread however I just recently purchased a 1975 C3 the people before me Installed and edelbrock Cam intake and carb As well as aluminum valve covers Chrome breather and a few other odds and ends I was looking to go back to a more stock look in one of the use the stock breather it would not clear under the hood and I found getting it to fit with store bought off the shelf items it was basically impossible I did figure out how to do it I think it looks pretty good If anyone is intrested what I did send me a message

 

Here it is

 

Absolutely the deal of a lifetime ^^^^^^^^^^^^^^^. Clean them up, some minor porting...very minor. and you are good to go....Save your money on the intake and spend it on cam/exhaust/heads....


As gkull says as well, the gm aluminum intakes are pretty darn good (all of them: LT-1/L-82) and do NOT expect any type of serious power increase wasting money on aftermarket intakes on stock or lightly modded motors. And no...they do not leak...what the heck?

 

100%

 

Absolutely 100% FALSE. THE l-82 was a quadrajet intake and the LT-1 Intake WAS A SQUARE BORE holley high rise intake. The only similarly between the 2 is they both fit a small block chevy and they are made of aluminum.
This has been debated since 2004 and settled long ago. The L-82 intake is the same as any other quadrajet intake except it was cast in aluminum.

 

I agree iwth this 100%. The stock heads have tiny ports and the cam barely opens the valves. Unless your intake is leaking or coming off for another reason (swap cam and/or heads), no reason to pull the original manifold.

I believe this myself. I've heard of another intake "patterned after the LT1" worth "tons of power", which is the ZZ4 manifold (10185063). It's a very high quality manifold in terms of fit and finish, has a fairly stock appearance, but it's easily outperformed by the basic Edelbrock Performer.

I've tried five different manifolds over the years:

1. Stock manifold on the stock L-48.
2. Edelbrock Performer 3701 on a Goodwrench 350 crate engine. I honestly couldn't discern a power difference between this engine and the tired L-48 that eventually self-clearanced itself to let the #7 piston take a new direction
3. Performer on pre-eliminator AFR 195 heads/mild cam, with headers.
4. The vaunted Weiand 7525 Team G manifold, otherwise same as 3.
5. The Team G manifold had a leak, so I went with the vaunted ZZ4 manifold.
6. ZZ4 manifold on a 400 small block with AFR 195 eliminators and a roller cam.
7. The Team G manifold again on combo 6, because I hate myself.
8. Edelbrock Performer RPM Air Gap (7501) on combo 6.

I wish I'd started with the Air Gap YEARS ago. It makes more power everywhere compared to the other manifolds, it's very high quality. If you're not concerned about having EGR or heat crossover, it makes installing the intake a breeze. Some of the passenger side manifold bolt-heads are a pain on cars with crossovers, particularly if you're dealing with the late 70's AC brackets.

Honestly, there's a reason everyone loves the RPM Air-Gap. It's phenomenal. Great low and mid-range response and pulls harder above 5000 RPM than my 7525 ever did.

Going back in time, you'll find a lot of love for the Weiand 7525, and quotes that suggest David Vizard said it was the #1 manifold for small block Chevy street cars. There's SOME truth to that. He modified a 7525 extensively and was able to create a very great combo. This is NOT true with the off-the-shelf 7525. Buy something modern like a 7530 if you want a single plane, but if you have a 75+ car a drop-base air cleaner and an RPM Air Gap make for an EXCELLENT street car. My 400 pulls hard to just over 6000 RPM. Completely changed the car.

Now, I'm wondering about AFR 195 comp ports or AFR 210s...

 

Shark Racer I am running a non modified ZZ4 engine that comes with the dual plane intake and using a Holley 670 Street Avenger.
This is in a 74 C3. Do you think installing an Air Gap intake would make a noticeable difference.
As it is now I have good power from 1500 rpm to around 5500 rpm.

 

I wouldn't make the change. The ZZ4 cam is specced to make power in a range where you may see some benefit, but the heads are basic L98 heads and wouldn't leverage the extra volume. If you ported the heads or went to aftermarket heads, I'd do it then. I'd recommend a different cam at the same time.

The L98 heads are better than 70's smogger heads, but not a lot. Their biggest advantages are weight-savings and compression boost vs the smogger heads.

 

^^^^ this ^^^^

 

I’m running the Torquer 2 with a 750 Holley on my big block ‘72. Stock height air cleaner. No clearance issues

 

I'll say this again, do not expect any big Hp/TQ increases with a manifold change alone, on just about any engine. It is not going to happen and the numbers do not lie. Here is another comparison test on a built SBC 406 engine with lots of performance parts and upgrades to take advantage of any supposed upgrade from an aftermarket intake:

https://www.hotrod.com/articles/dual...d-comparisons/

​​​​​​In this comparison^^^^ The Edelbrock Air Gap has no advantage over the ZZ4 intake:

Peak torque/ Avg TQ are virtually the same..statistically and realistically, no real world difference, certainly not any change that the driver would notice. Peak HP goes to the ZZ4 intake!

In another test I posted previously now multiple times, the ZZ4 outperforms or is within 5-7 HP/TQ of all the intake aftermarket players including Weiand, EDelbrock Performer, new and old design as well as the Edelbrock Performer RPM.

An intake change alone has consistently been demonstrated/documented numerous times over the years that on a stock to moderately modified SBC engine there is zero advantage with most intakes over a stock intake...NONE!

If I was to replace my mildly ported L-82 aluminum intake, I would hands down go ZZ4......The best deal and performer out there for the money and one that will fit under the stock C3 hood...

BTW-Others can comment, but there are very few aftermarket intakes other than the edelbrock performer and performer RPM, ZZ4, and a couple of others that will fit under a stock C3 hood. I'm not sure that the air gap would even fit under my C3 78 stock hood.....if I ever wanted to put one under there, which would not be my first choice.....

 

I can assure you an RPM air gap will indeed fit under. A 78 or 79 hood with a 1/2 " spacer and dropped base air cleaner.
I now even have a 5" filter.

 

Thanks for the reply’s. I had to try some different air cleaner base plates to get hood clearance after installing the Holley. I have also been told that the ZZ4 heads limit you as to what you can do intake wise.
The ZZ4 engine I have was installed in 1999 and has been a very good engine for me and made my Vette come alive compared to the L82.

 

I’m running the Performer RPM Air Gap(7501) on my 78. It fits. You need a drop base air cleaner, the stock single or dual snorkel intake won’t work.

The Performer Air Gap (2601) is a performer with the air gap tech. This will perform VERY close to a 2101 Performer until you hit heat soak, then you will see a little bit of benefit.

I’ve read this article MANY times. I used it in my own decision making process. You need to look at that article a bit more carefully - it’s got a significant misprint in it. The ZZ4 intake in the first chart shows peak HP at 471. If you look at the “Peak Torque And Horsepower” chart at the bottom of the article, it shows the ZZ4 at 451 HP. Vs 474 on the RPM Air-Gap.(7501) If you are looking to buy an intake manifold, a 23HP gain on a moderate engine is substantial. The RPM Air Gap also makes more torque @ 3K than the ZZ4 - meaning from 3000 up (and probably just a bit before) you’re going to see more power - and with that engine, the extra 23hp at peak really cements it.

I’ve got a ZZ4 intake, a Weiand Team G 7525 and a 7501 RPM Air Gap at my house. The ZZ4 and RPM blow the Weiand out of the water in terms of fit and finish. The RPM Air Gap does low, mid and high better than either of the two.

Agreed on stock. If your peak power is beyond 5000 RPM, odds are an intake will help. “Moderate” has a broad range of interpretations.

Please re-read my post and the article. You’ll see that’s not obviously the best path. Especially since you’ve got a ported intake already.

At Summit these ZZ4 intakes are $322. The RPM Air Gap is $289. You do have to eat the cost of another air cleaner, of course - so the Air Gap will end up the same or more expensive depending on which direction you go.

On my re-read though, there’s a point I was wrong on. The ZZ4 seems to do just a bit better than the 2101 Performer with the engine in the article.