I'd LOVE to get your 472 but shipping to Memphis would be horrible
For your 390, Just pocket port the heads, match the runners and back cut the exhaust valves and shave some off the deck to raise comp a bit.
I've got Comp and Bullet cams here that can regrind a cam, but you should be able to find a place by you to spice it up a little..
I missed a couple caddy's here in the past 2 years or so and should've gotten them.
Oh, and if the tail shaft of the trans is the same as the 70's th400, then a Gear Vendors overdrive would help TOO!
Great car! E