Performer rpm or M-1 intake

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Jkastelein

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Hey guys I got a 340 with and m-1 intake and thinking about swapping for a preformer rpm what do u guys think..? Will I gain more out of the rpm?! Thanks.
 
340-727. 30 over,10 1/2 to 1 sealed power pistons, Flat tappet Comp cam 484-294, Mopar M-1 Intake, 8 3/4 Sure Grip. 489 case with 3:55 gears, J heads, 750 edelbrock carb.
 
If that M-1 is the single plane, then yes I say swap it. the RPM will give you better low end with those gears.
 
What converter? The converter is a very important component in the intake decision making process. I would suspect that below 5000 rpm the Performer RPM will outperform the M-1. Above 5000 rpm the M-1 may outperform the RPM, but I doubt by very much, considering you are still running a factory head and your cam is not really radical. If you have a 4000+ converter, the swap probably won't make much difference. If you have less than that, a swap to the RPM would probably be beneficial.
 
With that cam, I'd bet there is almost no chance a single plane m1 does better anywhere except maybe the last 500rpm of usable and the 500 range is being generous. That won't make up for the giant hole down low compared to an RPM intake.

Plenty of people have swapped from RPM/AG intakes to M1's and the car ET was slower. MPH was almost identical.

If you have room, try the RPM with a 1" open spacer.
 
Instead of the preformer rpm I was looking into the preformer rpm airgap... And eventually getting a bigger can but I'm not sure on the cam... Any preferences?
 
A couple years ago when my car still had the 360 I was going to do a turbo setup so I swapped my RPM Airgap for an M1 single plane. Big mistake. The car lost 3 tenths in the 1/4 mile I could never recover, no matter what kind of tuning I did. The loss of torque was noticeable even on the street. It made the car feel sluggish down low.

IMO swapping to the RPM Airgap would be a good move.
 
Thumperdart said:
Now yer talkin..........Single all the way and maybe a "Thumperized" carb to boot...........:burnout:
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No way, not on a 340 with that camshaft. Ain't gonna have the legs to make that m1 work. An Ede Air Gap will mudhole the M1. BTDT, along with many others, got the t-shirt. :)
 
crackedback said:
No way, not on a 340 with that camshaft. Ain't gonna have the legs to make that m1 work. An Ede Air Gap will mudhole the M1. BTDT, along with many others, got the t-shirt. :)
Click to expand...

I agree here. your 340 will need the 4:10 rear gear and a 4000 + rpm stall converter along with better heads and ALLOT more cam before the M1 is needed. Even then the rpm might be a better choice for a street car.
 
crackedback said:
No way, not on a 340 with that camshaft. Ain't gonna have the legs to make that m1 work. An Ede Air Gap will mudhole the M1. BTDT, along with many others, got the t-shirt. :)
Click to expand...


My daily driver w/a stock stroke 360 and factory iron heads went 11.80`s -12.0`s w/an 850 dp, 2500+ stall vert, and the x-cellerator intake w/3.91`s many moons ago........
 
X-cellerator isn't near the upper end intake an M1 is.

Your DD would have been 2 tenths faster with an Air Gap. :)
 
Now that the comparing arguments are taking place, just what is this car used for? IMO, even with 4.10's and that purple shaft, I'd do a RPM-AG without a doubt, as someone mentioned, (LOL) Been there done that got the T shirt!

The M-1 can be a hell of a performer, but I'd leave it off in the street on a 360 with that cam and combo.
 
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