What, performance-wise, is the difference between Edelbrock's Performer and Performer RPM intakes? I'm looking at these as the new intake I am getting, with this cam? I don't know what is really required info when listing a cam's specs so I'll just list my whole sheet, and maybe someone can tell me either what what means or just what are important things :D

Crane 272 H10 Energizer.
intake/exhaust lift @ 3027 @ valve 454
--
cam timing @ .004: intake opening 27 deg. BTDC, close 65 deg ABDC. [tappet lift] exhaust open 67 deg BBDC, close 25 deg ATDC. both 'advertised durations' are 272.
--
Here are spring requirements, don't really need I don't think.
--
cam timing @ .050: intake, opens 3 deg BTDC, close 33 deg ABDC, max lift 105 deg ATDC, 216 deg duration.
exhaust opens 43 deg BBDC, closes (7 deg.) BTDC, max lift 115 deg. BTDC, 216 deg. duration.
--
Min. RPM=2000, Max RPM=5000, Valve Float=6500.
--

I know what the BTDC, ABDC, etc mean, but I know nothing about what the other numbers tell me or what I really need to know from this sheet. A mechanic has told me that this cam wants to pull a lot of air in compared to what crm my 2-bbl Rochester can provide (only 390 cfm). Someone told me that actually, this cam is probably performance wise worse than my stock cam, if I still have the two barrell carb. At any rate, I'm upgrading to a four-barrell setup. Is there going to a huge difference between a Performer or Performer RPM intake? And how much will a 4-barrell help with my setup? (355 cid, flat head piston, approx. 9.5:1 compression). Thank you.

Several people have used the RPM and then switched to a RPM Air Gap.Most have reported no change,while others have reported a very small drop in ET.

I think the only real benifit is in the hot weather when things get extremely hot under the hood.The underside of the intake runners are not exposed to the hot oil getting splashed up onto it.This could lead to a small increase in performance by keeping the air/fuel a little cooler.

If on a budjet you could get the regular RPM and then use a lifter valey pan (splash shield) under the intake plus a wooden or plastic carb spacer.

I've run that cam before in a 350..worked pretty good,more torque/hp over stock for sure.

the rpm is more of a mid-range intake. doesn't really lose any bottomend to the performer, but it makes more power from 3500rpms or so on up. with the cam you mentioned the performer would be good enough, but i'd still recommend getting the RPM instead, just in case you want a little more performance later on down the road. the RPM or Air-Gap RPM are the only intakes that i run on anything.

Originally posted by soccerguy045:
I'm looking at these as the new intake I am getting, with this cam? I don't know what is really required info when listing a cam's specs so I'll just list my whole sheet, and maybe someone can tell me either what what means or just what are important things :D

Crane 272 H10 Energizer.
intake/exhaust lift @ 3027 @ valve 454
--
cam timing @ .004: intake opening 27 deg. BTDC, close 65 deg ABDC. [tappet lift] exhaust open 67 deg BBDC, close 25 deg ATDC. both 'advertised durations' are 272.
--
Here are spring requirements, don't really need I don't think.
--
cam timing @ .050: intake, opens 3 deg BTDC, close 33 deg ABDC, max lift 105 deg ATDC, 216 deg duration.
exhaust opens 43 deg BBDC, closes (7 deg.) BTDC, max lift 115 deg. BTDC, 216 deg. duration.
--
Min. RPM=2000, Max RPM=5000, Valve Float=6500.
--

I know what the BTDC, ABDC, etc mean, but I know nothing about what the other numbers tell me or what I really need to know from this sheet. A mechanic has told me that this cam wants to pull a lot of air in compared to what crm my 2-bbl Rochester can provide (only 390 cfm). Someone told me that actually, this cam is probably performance wise worse than my stock cam, if I still have the two barrell carb. At any rate, I'm upgrading to a four-barrell setup. Is there going to a huge difference between a Performer or Performer RPM intake? And how much will a 4-barrell help with my setup? (355 cid, flat head piston, approx. 9.5:1 compression). Thank you. I'm running that same cam in my 327. You will like it! Since the cam peaks out around 5,000 rpm, you would be wise to use the Performer intake with it. Most of the benefit of the Performer RPM comes in the higher rpm's, so I don't think you would see much top end gain, and you may lose some lower RPM torque.

Do you have any idea what your rear end gearing is ?
If you are running an automatic but have say a 2.56 or 2.73 gear and simply cant grab enough RPM per second to really make that set up hustle then you may bennifit some from the small intake.If you have say 3.31 to 3.73's the larger runner intake may help slightly but as the others have said really only above say 3500 rpm or so.....My last 327 I ran a simular Crane mechanical cam ( 218 @ .050 ) and it would pull 6000 easily and I used a regular Performer and a Holley 390 CFM 4 bbl... Thing went absoutly nuts between 4000 and 6000 RPM.This with a lousy 3.07 gear and HR 60-14's ( 245-60R-14's ) 24 in tall.( short tires )

Originally posted by 69LS1:
Do you have any idea what your rear end gearing is ?
Yah, only 2.56. Am planning on getting a more mid-ranged gearing.

in my S-10 with a 350 i have a smaller cam than you are going to run. mine is .442/.420 with no headers, stock convertor, and 3.42 gears i picked up about a tenth at the track by going from a weiand #8004 to an RPM intake. i shift at 5200rpms. granted my truck is only 3280lbs with me in it, and it seems i lost a little fuel economy, but it does make more hp as it picked up my mph by 3mph with a slightly slower 60ft time, only by a couple hundreths. if it had a 2500 convertor it would be perfect.

graemlins/clonk.gif Silly me.
I kinda missed the boat on that one.
Thought you meant RPM to Air Gap RPM.

As others have mentioned Performer is a meant for lower RPM ranges and gas saving engines.With the cam you are considering The RPM would be the better choice,especialy with a 3.23+ gear.

Originally posted by thrasher:
graemlins/clonk.gif Silly me.
I kinda missed the boat on that one.
Thought you meant RPM to Air Gap RPM.

As others have mentioned Performer is a meant for lower RPM ranges and gas saving engines.With the cam you are considering The RPM would be the better choice,especialy with a 3.23+ gear. I already have this cam in my 350 actually, but am a little wary if it isn't too good with my current setup. Anyone have any HP estimates with a 355 ci with about 9.5:1 compression, and that current cam, with a 390 cfm 2-bbl? I'm wondering if it's probably restrictive and less than the factory 245 HP (I used to be able to peel out when already going 25 mph, and that was on my old, worn cam!). What will happen if I go performer RPM with a 4-bbl intake?

get the RPM intake and 3.42-3.73 gear and a 2500 stall convertor would be about perfect, IMO.

Going with a RPM manifold and a 600-650 Holley Double Pumper will add quite a bit of midrange torque and top end power.The low end may take a very small dip.

I would install them and then add gear.

I call that cam, Crane's "Little-Fireball" cam and it runs really good in a mild 327 motor!!

The really tall road gears won't help at all b/c you are just to tall imho, but once you have her going, it should still do OK..

My car had a mild .040" over, 327 with only about 9.75 to 10 to 1 CR. or so, a cast-iron 300hp/327 AFB intake with a cheap adapter and a good old 1850 600cfm Holley carb., a set of cheap Hooker four tube, long headers in it along with my M-20, 3/31's and about 26" tall tires and it ran very well once "up on the pipe" as the two stroke guy's say...

In fact the sucker ran like "Jack, the Bear" once a fire was built under her!!!

pdq67