I'm putting together a motor for my 66 coupe, which is a 250ci with forged flat tops and a 292 solid lifter cam. The head is fully ported and flows 231/184 respectfully. I want to keep it naturally aspirated for the time being, but I kept the C/R at 9:1 so I can add a S/C down the road.
For induction, I plan to use triple throttle bodies with dual injectors. One in the cylinder head, and one in the velocity stack. Using injectors in the cylinder head, which point directly at the back of the intake valve, improves emissions, idle and throttle response. While the injectors in the velocity stacks will increase top end power.
Using multiple throttle bodies cost more than a single TB, however they maximize air flow and allow for multi-point injection, in this case 12 point. I plan to use a plenum design that utilizes velocity stacks, rather than one that simply has the tubes welded directly to the chamber. Velocity stacks are a very important part of the induction system, as they increase the speed & volume of air flowing into the induction system (up to 19%), improve throttle response and atomization, and enhance torque thru-out the entire rev range. If you look inside the plenum chamber pictured above (and below), you can see the ends of velocity stacks.
Finally, I'll add a remote cold air intake using a high flow cone filter. Down the road, when I'm ready, I'll add the blower. I'm not sure which one at this point, but it will be very easy to adapt.
I estimate the induction system (manifold, plenum chamber, TB's, fuel rails, regulator, etc) will cost around $1500-2000, and will fit in a space no wider than 7 inches at the front, and 6 inches at the back. My goals are 350-400HP N/A, 450-500HP boosted, and 25-26mpg.
