2x4 intake

[Fuelie Fan]

There is a point of diminishing returns of throttle body sizing. As the throttle bodies get larger, the amount of throttle body opening to achieve 100 MAP gets smaller. So, whereas with 750cfm at 2000 RPM it takes maybe 50-60% throttle to achieve full load, with 2000cfm on a small block it will now take only 30% (all total guess numbers for illustration purposes only). In other words, you'll end up with "binary" or "on-off" throttle feel. This obviously also makes acceleration enrichment calibration very difficult. You won't make any more power than you would with 1000 cfm. As for low end torque, well technically the cam and intake should dictate that. Recall we're not relying on air velocity through venturis for fuel supply any more so low speeds through the throttle body are not nearly as important. May have only very minor torque losses, again plenum size plays into this.



It's certianly doable, though if you don't have to have the look of actually having 4 barrels in your throttle body, I would recommend using two stock GM 305/350 Throttle bodies and then just making an adaptor plate. This will give you just about 1000cfm total, and they come stock with 45 lb/hr injectors which would be a very good start for 350 hp or so, and you can always upgrade to 55 lb/hr or even 80's or 90's if you need. Hidden below an air cleaner nobody would know the difference. Just an option for those looking for the low-buck version.

Edit: Oops I think I just unknowingly recommended exactly what Turbo City has on their webpage. Surprising, becuase the one time I saw some of their work I wasn't too impressed.