What I haven't seen is much discussion on is the effects of a cowl hood combined with an open element and possibly a TB spacer vs volant vs stock. Would having a cowl hood negate some or all of the downside of pulling in hot air with the open element? I know how a cowl hood works in theory. I'm just not sure how much it would really matter in a daily driven truck vs pulling air from the fender with the stock or volant setup.
a true "cowl induction" system involves sealing the filter enclosure to the underside of the hood so the engine draws cool air from outside of the engine bay. Almost no one putting an aftermarket cowl hood on actually does this, they're usually just for clearance or looks.
THANK YOU!!!
There is zero point to having a cowl-induction hood that is not sealed to the air cleaner assembly, and with some kind of drain for rainwater/melting snow. All the OEMs sealed the ambient air intake to the air cleaner--Chevy with the Chevelles and Camaros using cowl induction, Pontiac with the TA shaker scoops, Mopar with their various cold-air intake systems, Olds with their "Ram Air" under-bumper ducting.
What nobody seems to think about, with all the air flooding into the engine compartment from a non-sealed "cold air" system like Cowl Induction, it makes the
radiator air intake less effective. If you look, even stock hoods have some kind of weatherstripping at the windshield end, to prevent air from entering the engine compartment and making trouble for the radiator air.
You can pretty much give up on the idea of better performance via TBI spacers, ESPECIALLY the kind that raise the injector pods on TBI units that haven't been bored-out to Big-Block size. The EBL tuning will be far more effective assuming it's done correctly. I can't help with that. The tuning should be done in conjunction with flat-top pistons, tight squish/quench, a better cam, etc.
The single-most effective power gain other than nitrous, would be a longer-stroke crank so as to build a "383".
I have heard that the TBI heads make more power than Vortec heads below 3500 RPM.
I'm not saying I believe that, but that's what I've heard.
I'd drop the TBI swirl-port heads like a broken rubber. But that's me.