Good afternoon Gurus,

I hope everyone in Oldsmobile-land is right as rain. Several weeks ago I picked up a 70' 350, along with it I received the Edelbrock 3711 Intake. My question is pretty simple, has anyone run across any fitment issues installing it on a 65' 330? My 330 is the high compression version and currently has the Edelbrock 1405 600 CFM carb. I was thinking maybe the intake may be a step up, so that's why I was wondering if anyone had experienced any adverse issues with the installation. The intake that's on it now is the original 4 barrel intake, but it's cast iron and based on 1965 intake technology, that is why I thought it could be a step up all around, not only the weight savings, and breath a little better than the old one, but also over all performance. Any way any insight provided will be gratefully received. Thanks, Doug

 

The 3711 Performer runners are no better that the ones in your original intake. The only difference is the lower weight going from iron to aluminum. A 7111 Performer RPM would be worth the effort. This one, not so much.

By the way, there's no difference between "1965 intake technology" and the technology in that Performer. The physics of airflow hasn't changed.

 

Well Sir,

Don't think I can argue with you at all on the point of "The physics of airflow hasn't changed." So, I guess I'd be better off with the 7111 and going that route then. Thank you Sir for the insight I'm grateful! Doug

 

Yes you would be better off with the 7111, those runners are still fairly small.
However I have to disagree with Joe. If you look at the runners on a stock Intake just one runner per pair comes directly off the plenum, further restricting flow.
On both the 3711 and 7111 all runner entries are closer to the plenum, putting them closer to a larger volume source, consequently with less restriction in between. While the performance gains will probably be modest, I believe even the 3711 has its advantages.
Note; this is a test I plan to do in the future(I wanted to do it before but ran out of time). First would be stock iron intake, next the 2711/3711 intake, then a 7111, then maybe a HSD. It’ll happen someday, I hope😎

 

I'd love to see real test data, because admittedly we're all just "eyeball engineering" right now. I guess I didn't realize how small the runners were on the 64-65 iron intakes. The later intakes have larger runners. Here's a comparison of the 3711, stock 64 and a stock 71 for comparison.

 

Something that has been bugging me for quite a while now. not about intakes but about photos. Almost all of the photos posted here I can't see - just a blurry image with a "play" arrow button in the center, which gets replaced with a ring of dots going around and around. But in Joe's post above, only the top photo is like that, while the bottom two are perfectly fine.

What's up with that? I had just figured I needed to update something or other, add a plug-in, something something. But having both the unloaded version and perfectly fine photos in the same post makes me think it's something else.

Surely this has been an issue for others that has been solved?

 

What browser are you using?

As for the two that work for you, I stole those from another thread here at CO. The first picture is linked from the E-brock website. Apparently that matters.

 

That narrowed it down enough to fix the issue - settings on my computer. Hey, I can see photos again!

 

Note; this is a test I plan to do in the future(I wanted to do it before but ran out of time). First would be stock iron intake, next the 2711/3711 intake, then a 7111, then maybe a HSD. It’ll happen someday, I hope😎

cutlassefi,

That would be a very interesting comparison test of which the outcome may not be the deltas one would think of observing. Still, it could be surprising, interesting to see the actual numbers that would generated though. Keep us posted if it comes to fruition, I'd like to know the outcome. Thanks for the insight! Doug

 

So Joe,

Observation utilizing the visual comparison of the runners, primarily between the 3711 and the 64'/65' iron intake, does that make you think there would be any advantage (besides weight savings and a cleaner looking installation), using the 3711? Thanks for the visual! Doug

 

One consideration that may become a big discriminator is that the Edelbrock Carb won't work with the 3711 manifold. I believe it is due to the throttle linkage and the EGR boss. The instructions even say their carb won't work. A holley fits just fine on the manifold. A spacer may help, but that adds other issues (air cleaner selection/height, carb studs, throttle cable brackets, etc.)

Something to think about if the edlebrock carb is working for you already.

 

Unfortunately when I bought my 3711 Eddlebrock mentioned nothing about their carb not being able to fit. I used a spacer of around .75” and made a clean cut at the bottom of the linkage. I connected the spring at the top of the linkage to pull from the front. It works well but it angered me to no end that nothing was mentioned anywhere that their own parts won’t work with each other.