I (just yesterday) ordered a 3 row all aluminum one for my 12.
Looked at a lot of them, many admit to the tanks being somehow "bonded" instead of welded, this one is only one on eBay that claimed 10 year warranty, all TIG welded, supposedly aircraft grade aluminum.
My 12 1/2 ton with it's (ugh) 4.7 seems to have been running a little warmer than usual lately compared to the previous 2 years when I first got it.
And that's without my camper on the ball, and the midsummer temps. This is my 1st 4.7, I have heard the horror stories on them, trying to head off the valve seat problems that I hear so much about.
I put a "champion" 3 row in my fury about 5 years ago and it stays almost too cool... Though that car never gets driven in temps where I need the heater ...