by Sirshredalot » Mon Jan 07, 2008 7:58 pm
Its been my personal experience that single planes DO perform well at low rpms. My truck weighs dang near 4000 lbs....especially with everything that i haul in the bed.
I had a 355 with about 8.5:1 compression and a very mild cam with a wide LSA...114*.
I went from a perfromer Q-jet manifold to a Weiand IMCA single plane with an edelbrock 1406 600cfm carb....vacuum advance stock distributor and not only did I not lose any low RPM torque....I gained ALOT of midrange and fuel mileage.
The truck had a 28" tall tire, 2.67 gears, and an overdrive transmission.
First gear was a 3.09, manual transmission.
I knocked down 22-23 MPG cruising at 1800rpms in a heavy truck with at least an average of 500lbs in the bed.
The SBC has a very efficient firing order IMHO, as do most vehicles with a 18436572 firing order....Ford engines have trouble with low RPM torque when used with mild cams and single planes because they have a different intake pulse pattern....Im not sure if that is the sole reason for it for im sure it contributes.
Also the SBC style intake pattern with the grouped runners provides a more consistant runner length than a staggered intake pattern like a ford or mopar.
I noticed that your intake shares the middle two runners with the outer two isolated....uneven runner lengths.
You can extend those runners by welding small aluminum squares to the runner walls and extend them into the plenum to lengthen them.
Also doing the same thing on the wall where the outer two runner joint at the tight angle will further extend the runner length.
The longer the runner....I feel....the lower the rpm that peak torque will occur.
also the cam has alot to do with it....a cam with a wider LSA like 112-116 with have more signal and more low end than a peakier cam with a narrower LSA like 106-110.
Regardless I think that even without mods to your intake, you will be happy with that intake. The car is light with more than enouh rear gear and tranny gear to make it happy.
God bless
-Shred