I guess I should be excited about the wheelstander, but I'm unlikely to build one that way. Still fond of the kit though. The CMG car is a Dodge 330, no? No such thing as a Dodge 300, unless you count the D & W series trucks.
That's a 426 Hemi, a totally different engine. There were no tunnel rams for early Hemis in the '60s, other than DIY efforts like the Ramchargers setup. Aftermarket tunnel rams were developed for MP and Pro Stock applications using then-current production engines - BBC, late Hemi, Boss 429 etc. so there would have been no demand for one for an early Hemi. Gassers still using early Hemis in the late '60s were mostly blown or ran fuel injection.
I like the old Revell '57 and I think it's the best of the three. The '55 looks a bit flat fronted and the fit of the doors and body parts on the '56 was abysmal. The biggest issue to me with the '57 is the clunky front bumper. I''m inclined to dig one out of the stash and build is as a bumperless gasser, like the one I did 30 years ago and lost.