320 head flow numbers

**saltracer** · 03-17-2009, 03:17 PM

Anybody have flow numbers on a stock 320 head............and/or thoughts on improving those numbers ?

**36 Century** · 03-17-2009, 05:59 PM

139 CFM at 28" Water at .500" Lift on intake.

70 CFM at 28" Water at .500" Lift on Ex.

Our Drag Race/Boniville head is at

207 on Intake

160 on Ex.

Raise the roof, and braze up the area around the head bolts so you can raise even farther than the original casting on the ex.

On the intake, We took a boring bar and enlarged the 4 Openings about .375" then soldered up where it went into the water, and worked the bowels from there.

**Jim Carmichael** · 03-18-2009, 08:45 AM

At first I thought the reply contained a typo but figured it really would be a "gut wrenching" job.

**Jyrki** · 03-18-2009, 11:27 AM

It's amazing how bad the stock numbers are, but even more amazing how much you could improve the exhaust!

What are the valve sizes on the ported head?