MikeC

In the intake manifold.

Are there any real benefits on a 400HP street engine? I have the engine apart and I am thinking of milling down the divider on my Edlebrock RPM intake. I am gasket matching the intake ports to a Felpro 1205 which is a good fit to the Sportsman heads I have and I started wondering if milling this down would be a benefit.

Also how far down shoudl I mill it if I do it?

norvalwilhelm

I milled down a old high rise LS6 intake just like they did on the L88 intakes. The center divider was milled down about an inch. That was a great intake and when I upgraded to a single plane Victor Junior I lost performance.
I liked my milled down intake.

MotorHead

Take a look at the RPM Air Gap, there is 2 inch section milled down 1/2 in. It must work because the Air Gap only gives up about 5 HP @ 6500 HP to a Vic Jr on a 500 HP small block

MikeC

Yeah I was just looking at the Air gap in the Summit catalogue.
I'll put it on the mill at work on Friday.

GDaina

Yes, you gain upper end performance at the expense of some mid and low range

yellow 72

I remember being told by a reputable engine builder, that with cam durations over 240* @.050 and if you spin it over 6000, removing the divider will help

big_G

I had to modify the center divider on a Performer rpm this way to fix a tricky fuel mixture distribution problem between cylinders. This was a popular mod. in the late 60's and thru the 70's.