Sources for pre-09 5.7 long blocks / cores?

Are you sure your TTI's are for the small port 5.7 heads only? Could be they sold different sets before, but as of right now what TTI sells is for all G3's (5.7, 6.1, 6.4, 6.2). I would bet your set fit both the 5.7 and 6.1 as at the time that's about all the G3's being sold, and the 6.1 uses the same exhaust port as the 6.4 and 6.2 and the Eagle 5.7. If your set fit both the 5.7 and 6.1, they will fit an Eagle 5.7.

But it is true that the '08 and older 5.7 had a smaller exhaust port than the 6.1 and later motors.

I like the Eagle motors, VVT adds some, the crank is stronger, heads flow better. But I would want a 6.4 intake as well and that isn't going to fit your car without notching the firewall or locking the SRV flaps into one mode. And an aftermarket cam for the VVT block is more expensive than for the earlier block.

If I were spending your money knowing that you aren't opposed to an Eagle motor, I would re-ring an Eagle 5.7, stab in a 6.4 6M cam and the Mopar valve springs, swap over to a car TC cover (and notch your frame rail for alternator clearance) and run either an Eagle car intake or a 6.1 intake. It will add complexity to your radiator hose routing as the upper outlet points the opposite way of the truck one, but you could swap to a late model radiator or run the long upper hose like the trucks or Jeeps did. And you will need a different oil pump pickup to fit the later pump, but the rest of your oil pan setup will bolt on. Other than tuning, I don't think there are any other snowball triggers to watch for.

It would be a departure from your current look, and not sure about the lope. I like how a stock Scat Pack sounds, and this would be close to or maybe a touch more lopey (smaller motor, same cam), but it's just my opinion.