I have a 22" core opening in my Challenger (a T/A clone I did back in 1978... was a 318 car, no A/C), and have used a couple different radiators all at 22" (typical stock designs).

Just recently, with a new 410 SB, I purchased a new U.S. Radiator (aka Cool Craft). Special ordered their "Tripple Flow" aluminum rad, having two 1" cores. I favored this brand because the tanks appear near to stock. The brackets needed slight slots opened up, no big deal, to mount to my factory original core support. The 22" factory shroud fit about 95% OK. I did notice that the rad core sits closer towards the engine, as opposed to the core support.. in other words, its not centered... having some extra space between the core support and the rad/tank.... I've decided to live with that... it could've been closer to the core support... I plan to install a top cover/shroud between the upper tank-to-core support. I painted the rad with Eastwood RAD black (after first using a primer).... looks very good overall.

While idling, driving on roads/hwy, etc.... no problems, stays cool (using a 180 thermst). I have an aluminum Chrysler 7-blade clutch fan (light weight..!) and I installed the Hayden short shaft Muscle Car clutch unit... that unit is a hassle to fit the bolts to the water pump... just barely any room.. and the face of the clutch unit sits too far away.. about 2" from the rad. The blades of the fan are inside the shroud only about 1/3 of the way... perhaps too short. But, at normal driving, its cool. (I may re-install my 6-blade large/wide aluminum flex fan w/spacer to see any difference, but... the recent racing rules have banned flex-fans... for safety reasons... I've never had any problem with it before).

I've just ordered a new Hayden HD clutch #2747... to bring the fan closer to the rad.. see if that will make any difference.

My recent dilemma is that when I do HPDE (road course lapping sessions for typical 20-minute sessions typical rpms 4000-5700), the temp goes up... way up (especially on hot 80-90+ days) ... so that I should turn the heater motor on full blast to reduce the temp a little (windows open!... hot inside car ... but not really that bad). I do have a large full width automatic trans cooler in front (fits perfect.. from a Dodge Cummins diesel PU)... all vanes are cleared and clean. I'm planning to make and install an upper cover between the grille-to-core support so to keep more air towards the rad (I see this setup on lots of road race cars, including the Posey T/A and similar vintage TransAm cars). I may also make some funneling walls behind the grille-to-rad to funnel more air directly to it.

I've considered installing a 26" wide rad... US Radiator has a setup to adapt to the 22" core opening... I just wish the engine would stay cooler during aggressive lapping HPDE sessions.... on hot days.

Maybe a cross-flow rad would be better.. even if it is wider ~26" vs 22".

Mopar Mitch "Road racers and autocrossers go in deeper and come out harder!"... and rain never stops us from having fun with our cars... in fact, it makes us better drivers! Check out MOPAR ACTION MAGAZINE, August 2006 issue for feature article and specs on my autocross T/A!