So, who has tried the Perf RPM Air Gap?

[ratio411]

Little backround:
Dad's Spyder has run several intakes, from a cast iron 327 Q-jet, a Weiand single plane, to a regular Performer that is on it now.

Personally, I like a single plane on a small engine/light car combo... However, I don't intend to upgrade the gearing, cam, or heads anytime soon...
So I am willing to consider an 'aggressive' dual plane. Anything but the plain jane Performer!

I have used a Performer RPM before, and wasn't impressed.
Is the RPM A/G more aggressive than a non-A/G RPM? If so, it still has my attention. If not, I'll just get a mild single plane.

I like the idea of blocking the heat from the engine. I didn't install this intake that is on the car now, but when I put an intake, I always block the heat riser.
I live in Florida, so heat risers, and even EFI anti-icing systems are overkill, as well as power sappers.

Anyway, are you happy with the top of the line RPM A/G?
What is hood clearance like? (I have a scoop, but wouldn't mind going back to stock.)
What kind of rpm can you get out of your V8 with this intake, and still be building power?
Reason I ask:
I noticed when I swapped from Torker to a Perf RPM once before, that low end power was no better, and after about 2000 rpm, the engine felt sluggish.
Net effect was a 'doggy' feeling engine compared to the Torker (old style). So I swapped back to the single plane.

Thanks!
Dave

[ratio411]

FWIW:
I have 3.08 gears, TH250 (?) air cooled with tiny Vega converter that stalls relatively high behind the 350, 1.5" Hookers, cast iron 350 heads (don't have a clue how to tell versions apart), and run a 700 DP Holley. Cam is unknown, and if I had to guess, the valves are the 1.94" flavor. The engine is a 350 out of a 73 Chevelle.

[chevy art]

if you want to listen, i would tellyou to definitely not waste money on any single plane for a small block(street engine) unless you have at least 400 cu in and some healthy engine parts like cam heads etc. with the combo you have i wouldnt even waste the money on an air gap or an rpm air gap. just get yoursely a regular performer intake with a 600 cfm holley of edelbrock carb. bet your car never sees over 5000rpms and with the engine combo and gears you described, then this manifold should be your choice. this is exactly what i would do if it were my car. . hope you think about this combo. trust me it will work if all is as you said and all parts are in good working condition art

[ratio411]

if you want to listen, i would tellyou to definitely not waste money on any single plane for a small block(street engine) unless you have at least 400 cu in and some healthy engine parts like cam heads etc. with the combo you have i wouldnt even waste the money on an air gap or an rpm air gap. just get yoursely a regular performer intake with a 600 cfm holley of edelbrock carb. bet your car never sees over 5000rpms and with the engine combo and gears you described, then this manifold should be your choice. this is exactly what i would do if it were my car. . hope you think about this combo. trust me it will work if all is as you said and all parts are in good working condition art

I appreciate your opinion.
What I wrote in the first post was my experience, tried and true.

I have also run a single plane on this car when it was a 305/4 speed with the same 3.08 gears, and had a similar experience due to the car's light weight.
I am not approaching this blind. My experience is that even though the higher winding parts, like a single plane, really shine over 5k as you suggest, they
also out perform the 'street' parts at relatively low rpm as well. Again, with a smaller cubic engine and light car, the 'torque' parts are overated.

If I was dealing with a car 1000# heavier, it would be a consideration.

[Rickracer]

There are really too many unknowns in your combo to make any realistic suggestions, although I can say for SURE the the 700DP is overkill. You really need to find out what heads and cam are in it, and if you want it to run GREAT, think about a head and cam swap. On a 73 350, that about as low compression a motor as you'll find, with terrible heads, (as a rule). Find yourself a pair of Vortec heads, and slip in something like a Summit 1103 cam, with a Vortec Performer or RPM intake, and you'll likely find about 60 to 100 more hp, depending on how bad what you have now is to begin with.

[wrightway]

I have ran as fast as10.20s with an air gap on a 406 with a .600+ lift cam
in my under 2600 pound car the air gap is capable of a lot more motor than yours
Air gap is the best of both worlds (street/race)

[chevy art]

air gap can be the best of both worlds if you live at 6500(or under) rpms. beyond that rpm it would be foolish to use an air gap manifold(dual plane) sure would like to know more about the 406 cu in engine that runs 10.20s in the 2600 lb car. i just had two(2) 406 engines built with good alum heads and roller cams and big single plane intakes and all other good parts and i also own a 377 cu in sbc with all good parts(625 hp) and i will reall have to push the cars to get 10.20s. would like to know all about the car and engine that runs these e.t.s. not doubting you. i always look for tips on how to go fast art

[wrightway]

air gap can be the best of both worlds if you live at 6500(or under) rpms. beyond that rpm it would be foolish to use an air gap manifold(dual plane) sure would like to know more about the 406 cu in engine that runs 10.20s in the 2600 lb car. i just had two(2) 406 engines built with good alum heads and roller cams and big single plane intakes and all other good parts and i also own a 377 cu in sbc with all good parts(625 hp) and i will reall have to push the cars to get 10.20s. would like to know all about the car and engine that runs these e.t.s. not doubting you. i always look for tips on how to go fast art

Art more details in this post for you
viewtopic.php?f=1&t=26263&start=0

[72 SS PNL]

i like the factory LT1/Z28 intake , which holley made a copy of , the performer rpm is loosely related to rpm wise 1500-6500/7k

the air gap looks better and would help some with the intake temp , but i still consider it a looks feature over function , a valley pan to help keep oil off the intake helps just as well

[chevy art]

eric i would think that the runner design in the rpm and rpm air gaps are far superior to older designs. just last year there was a dyno report on alot of the currently available sbc intakes, and the lt-1 and z-28 intakes(same designs) produced 20 horses LESS than all the modern design dual plane intakes. they may have been the king of their day, but now they are really only worth using on numbers matching cars for originality.they are worth some decent money to the collector car and muscle car guys that build the sbc engines for these cars. art

[72 SS PNL]

dont think ive ever seen that article art

id still put my Z28 intake against other dual plane intakes

[chevy art]

eric i will look for that article. i save all the good articles like that one for future reference. if i find it i will copy it and get your address and mail it to you. positive i have it . the rpm air gap is definitely the king of the hill in the daul plane category. art

[Lespaul59]

Those air gaps are designed to keep the carb. cool and nothing else. Got one on my 79 spyder and I knew it is pretty much a basic dual plane intake but since I had vortec heads on it, My friend had an extra one. The heads are gonna take whatever they can handle. Be it nitrous or a 671 blower but a intake with a carb doesn't give much horsepower.Not on a basic 355 build up.

[chevy art]

hey les paul 59 probably with the stock exhaust manifolds you could get away with just using a regular performer manifold and not the performer rpm or rpm air gap. that would be , of course , if you only went up to like 5500 rpms or less. dont know what your cam is. that would be the determining factor for you rpms.just my thought art

[Lespaul59]

The cam is a .470 .470 lift. GM SAYS NOT To go over .480 lift on them so I got it pretty close. Just a basic 71 010 block 4 bolt main truck block with .030 over. 4 EYEBROW FLAT TOPS. nOTHING TOO RADICAL BUT SOMETHING THAT SHOULD PUT OUT AT LEAST 300 HORSES. I hope.