Difference between Air-gap and RPM Performer

[RDJ]

I'm curious what the difference is between the Edelbock RPM Air-Gap (7576) and the Edelbrock Performer RPM (7176). They are both dual plane rated at 1,500-6,500 rpms.

Which one is better for my build, and, is one taller than the other with the potential to not be able to close my hood? 1967 Barracuda.

Planned engine 360 LA block, 408 stroker, Edelbrock heads, Hughes 232/237 @0.50, 540/548 lift 110 lobe cam, 10.3 compression, TTI headers, 3.23 sure grip, 2800 stall converter.

A little history, I was originally planning to do a stockish budget build with some Magnum heads I have, so I bought a Professional Products Crosswind intake (rpm-airgap copy intake), because the Edelbrock Magnum rpm intake was about $400 and the Crosswind was only $180.

But, after much reflection, I am going full on with the engine. Now that I am going with the LA style Eddie heads, the Edelbrock intakes are $225-$260 (depending on which model). Not much more than the Crosswind when you take into account the amount I am spending.

First of all, I have read mixed reviews of the Crosswind. Some say it is fine, no problems, and just like an Eddie RPM. Other reviews say they are not the best quaility and the real Eddie RPM works much better.

So, is is worth the extra $$ for the real Eddie RPM, or would the Performer RPM be better anyway?

 

[dgc333]

RPM and Air-Gap are the same except for the gap under the air-gap. If your plane is to drive a lot in cooler climates the RPM will warm up faster and provide better driveablity, the air-gap may give a little more power because it can keep the mixture a little cooler.

The CrossWind has slightly smaller ports than the Air-Gap/RPM so is better suited to a milder build. FWIW, I am using a CrossWind on my magnum headed 360 and am completely satisfied with it.

 

[goldduster318]

I have the magnum air gap #7577 and it fits fine under the hood of a 70 Duster (I have a 600 holley and a 72 340 air cleaner).

There pretty much isn't a difference between the two other than the air gap as opposed to being solid aluminum. If they are the same price, I'd buy the air gap.

 

[MopaR&D]

The air-gap will keep the intake charge cooler but you have to watch out in colder weather because I'm pretty sure they don't have provisions for exhaust crossover or anything like that. I thought about this intake before for a future 360 build and wondered if it was possible to rig up some under-plenum electric heater thing (sort of like a block heater or electric choke) for cold-weather starting and driving.

 

[ckj688]

I have an air-gap and have driven in pretty damn cold weather, doesn't seem to have any problems thus far.

 

[moper]

if you're driving every day, you will notice when the temps go down below 35 or so. A choke on the carb fixes the starting issue.

 

[ramcharger]

OK, here's the deal. I used to live in Chicago and had blocked off the manifold heat on a Ford 400M with a Crane Fireball cam and a Holley Street Dominator manifold. Not quite the combo for -20 weather, lol!

I would literally get frost below the primaries in any weather below 20F. It would stall from the freezing blocking off the idle hole and transfer slots, I'd let it sit for 5 min, start it again (with much pumping, no choke), and it would be OK. WARNING!!! The frost did hold the primaries open more than once.

Just my real world experience.

This may not happen in drier enviroments.