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I'm bumping up the performance quite a bit on my W, and was wondering if there's some happy medium modifications with the dual plane that'll still maintain the good low-end flow, plus provide better high-end flow. Anyone modified the plenum? Just curious... Eric.

79 block .030, .012 recessed pistons, GT40P heads, Lunati barebones cam .214/.224 @.050, .472/.496 (add .03 for 1.7x roller rockers), 115 lb springs closed, 8.15" hardened pushrods.
 

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It would be a waste of time in your case. Your mild cam will run out of power before that anyway, so winding it tighter will just be a waste of time, literally.

While winding the motor high sounds good and sounds like it is making gobs of power, you'll find that shifting at more moderate RPMs will achieve better ETs. That's because of where your engine produces it's best torque. It is torque that gives you the rate of acceleration. With a 214/224 duration @ .050, you'll probably do best around 5000rpm. That's well within the limits of a Performer or Performer RPM intake.

If you try putting a notch in the dividing wall between upper and lower sides, you'll weaken the vacuum signal to the carburetor low-mid RPM metering and take some of the neck-snapping low end power.

If you feel the need to try anything non-reversible (something that can't be changed back easily), start by trying a small 1/4" or 1/2" open plenum carb spacer between the carb and intake.
 

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x2 - W's are known to let go slightly north of 6K anyway.....also the cam and stall on the TC need to be as closely matched as you can to take advantage of the part of the torque curve where your intake flows best. Typically it'e the exhaust and heads you get more bang for your $ anyway.
 
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