I still have worked Edels on my 489, and they run well, but the TFS would stomp them for far less cash than I spent with KC in 2006 when they were the best we had.
Unfortunately for Edelbrock in this case, not improving a product makes you obsolete over time. (if they are competitors) Two ports with similar volume, one flows 70+ cfm more, and has a modern chamber, you gain everywhere.
That being said, I haven't tried a big TFS intake valve with a cheap piston, that generally works with an Edelbrock, so there is some benefit there for head swappers, and in a truck, you still get 30 cfm from a C8AE-H to an Edelbrock, but if doing a whole build, you get 110 cfm from a TFS. Edelbrock basically sold CJ heads to the masses, which is a good thing, but they don't compare in performance or individual parts quality in the assembled TFS heads
Great question on mileage, the port volume is similar, but with a bigger bowl on the TFS, so I would assume the port itself is a little smaller, especially seeing the small flow directors in there. If that is the case, part throttle torque would be up, flow numbers certainly are at low lift and torque certainly is at WOT, so maybe, but can't imagine it would be a ton of mileage from the port itself.
I would throw this out though, the cam to make X amount of HP will be smaller with the TFS, so if I was in a 4x4 pickup ad the price was the same, nowadays, I'd make the power with less cam and compression with the TFS heads over the Edels, and at the same time, benefit from the better chamber and resulting less advance requirement. When I did my C8AE-Hs they flowed 277, and those heads work great because the intake port is fast, small and efficient after porting. The TFS, would likely be that on steroids and need even less overlap and lobe for the same power
