Look at what @ArizonaBOSS and @ls110 have for radiators. Also look at Drew's grille.

Just say no to bent fins - Get some Nomex honeycomb!

Fluidyne and C&R would be at the top of my list.

C&R:
http://www.lethalperformance.com/c-...-5-0l-high-capacity-performance-radiator.html
http://www.lethalperformance.com/ford-boss-302-mustang/2012-2013-boss-mustang-302/cooling/radiators

Fluidyne 3 core double pass :
http://store.kennybrown.com/product...ble-pass-full-race-radiator-2005-2014-mustang

triple pass:
http://store.kennybrown.com/product...ple-pass-radiator-2005-2014-mustang-gt-and-v6

This is what I'm using FWIW.
https://www.brothersperformance.com/2005-14-mustang-gt-fluidyne-triple-path-aluminum-radiator.html

I'm happy with the one from Capaldi Racing

http://shopcapaldiracing.com/capaldi-racing-aluminum-radiator/

I would love to upgrade my rad to a race spec one, but but with my recent off road trip I have to keep a tight control on the addiction for more race goodies! When I can, I think I will go with the Boss OEM $223 CR3Z-8005-A rad. I confirmed that its the same OEM boss rad I have that, has not given me any problems so far. Once I fix my car I will be in a new class that has two 15min sprints with a 10min cool down period in between. Will get the Nomex honey comb though, I should have got it ages ago.

I estimate that I am only at some 425rwhp so its not anywhere as extreme as some of you guys!

I bought the Capaldi radiator from Bill. Should go in next weekend.

I will be installing the nomes honey comb.

Anyone know the size of the honey comb?

Any specific sites for the Nomex Honeycomb?? I think our rad size is 20" by 24", will check tonight.

Got mine from speedwaymotors.com in 22X31.
I know there's a thread here somewhere that discusses the nomex honeycomb in detail.

Thanks. I would like to have before I get home. Will order today

And use a kit like this to install it:
http://www.speedwaymotors.com/Honeycomb-Mounting-Kit-for-Transmission-Coolers-Fans-Shrouds,4405.html

I didnt use any of the zipties, even though I had some on hand. I cut the honey comb wide enough that the stock radiator shroud held it in place nicely, and with the bottom aero panel in, it wasn't going anywhere.