I use a C&R heavy duty radiator and I know of several who use that or a Ron Davis radiator for their blown Z's. I'm referring to the C5Z now so I'm not 100% sure if they have applications for the C6Z. I'm betting they both do.
I run a De Witt's radiator with the left side EOC in my C5Z with a 416 stroker.
Quality all aluminum piece, very easy install and it works very well. With a 160 t-stat, my coolant never gets above 200 even when I'm flogging it on the road course in the summer heat. Highly recommended. :thumb: