[Cliff R]

"I'd imagine the issue for many would be hood clearance...add spacers and try and cobble up air cleaner assemblies."

Correct, the RPM is too tall right to start with to clear the hood on most of these vehicles and REQUIRES "cobbling" with Ram Air and Shaker parts. We are over here in the "Street" section so the owners of most of these cars haven't taken a saws-all to the hood yet to clear most of these parts.

I'd also add here that IF you find yourself adding a drop base air cleaner or move the air cleaner lid closer to the carb you are killing off a LOT of power with some set-ups.

NO ONE tests any of that stuff unless they are racing the car and have a car that will hook and run the numbers right to start with. I've tested everything out there that will bolt under my factory Shaker hood and you do NOT want to know what I've found with many of these parts, especially drop base air cleaners, funky flow thru lids, spacers, etc.

I've actually tested 4 spacers back to back at the track on both single and dual plane intakes with Q-jets and Holley carbs. Like running a fully open spacer on an RPM. I couldn't make a clean pass with one even though it pulled really hard on top end. It induced a "stumble" or hesitation going quickly to full throttle that wouldn't tune out. Keep in mind when reading that comment that most folks are looking to "feel" the secondaries "kick-in". I'm tuning for no felt transition whatsoever, just smooth/seamless power from idle to the shift point. That deal will run quicker ET and MPH every single time.

We tried it on another car we were running that day (private track rental) and it did the same thing. Sort of puked on itself for a second then pulled hard thru the gears to the finish line. Both cars LOVED the semi-open spacer in contrast, divided across the front and open between the secondaries. They also ran very well with a Tomahawk, 1" open spacer and 850DP carb even though they lost a little 60' we were seeing a solid 2mph on top end and very close in ET.

So you really never know with any of this stuff what's going to be the best in actual vehicle performance once you leave the dyno room and get the vehicle on the track. For bragging rights on a dyno sheet we usually top the engine with a T-II, 1" spacer and 850cfm Holley and lighten up the dyno a bit so it can rev.

If it's a higher end "race" engine just bolt a Victor/Dominator on it and hand that dyno sheet to the new owner......FWIW.......