You can order alum radiators in a wide variety of sizes, also as standard OEM replacement sizes. I chose to go with an AFCO Racing alum rad (non epoxy) 19 x 26.
They modified it for me by eliminating the filler cap, adding AN fittings instead of hose fittings and installed a petcock drain. Cost me 255.00.
I originally had a Griffin but it leaked and I chucked it.
http://www.afcoracing.com
Roscoe