Thrift,
It shifts from "LO" to "HI" right after the 330ft mark at about 4500rpm, goes thru the 1/8 mile in "HI" at 2900rpm or so depending on the run.

Doesn't exactly get air under the front tires, but my goal in the testing was consistency not low ET so the setup is ok for now.

I mount the carb sideways so the primaries are outboard, trying to make the runner lengths closer to the same while cruising. Not sure how much it matters but that's how I did it. The Offy is a little closer to the valvecover than the Cliff but both of them have plenty of clearance.

Here is a thread discussing some of the testing and a picture of the carb mounted:

https://www.inliners.org/ubbthreads/ubbth...=true#Post61158

The 4100 Autolite is the "longest" carb so sits closest to the valvecover but it does fit even with the Offy. The Holley 4150 is shorter as is the AFB carb.

To mount front-rear or side-side you just take the carb adapter plate off the intake and turn it. Hope you realize that the adapter plate is a SEPARATE PIECE from the intake so you might have to order them separately, yet another chance to help out the economy.....