The car is a 1970 challenger 484 hemi f2 procharger 95 % street only want to do this once . What do you recommend ?

I replaced my factory radiator that couldn't keep my hemi cool with a champion 3 row in my 70 cuda and it works well, but I'm not procharged. Fit was good and only had to drill one lower hole.

prcracing.com is where I got my latest one. made to the measurements I provided, angle of hose connectors, built in trans cooler.

Is that the maximum window width of the bulkhead, or just of the existing radiator?
More width is the most efficient way to get more cooling (better than thickness).

That is the rad support . I would go thicker, got 2 1/2 inches more till I'm at the blower pulley as for width from factory holes I would assume I can go wider to the pass side only

I run a Mancini Muscle Car Radiator. It is a top tank style high performance AL radiator. It works quite well with a warm 496 and AC... including desert runs. Uses factory re-pop hoses as well.

These are available in both 22" and 26". Mine is a 26". An effective cooler.

I agree also that opening the core support to 26" would help though you may get it done with a 22".

Details seem to matter a lot on cooling systems. A high volume water pump slightly overdriven (~7%), thermal clutch fan and good shroud works well for me.

I've had 2 brass radiators built by US Radiator. They look stock, and both use shrouds and factory thermal fans. I did use Spal's twin fan set-up with shroud and Controller on the 26" radiator successfully for 6+years, but swapped it back to the factory style thermal fan set-up. It wasn't cheap, but you better have a good electrical system & feed to supply it with over 40 amps on start up.

The quality and cooling performance is top notch. One car uses the 22" opening and cools 510 hp and an auto trans. The other cools a 700+hp motor with a 26" opening and a 5 speed. Both have A/C condensers in front of them.

Give them a call, and explain what you have. They will tell you if they are able to build a radiator for you that works in a 22" opening. I'm sure a lot depends on the fan system you will be able to use.

Are you going to be able to run a shroud and factory clutch fan? If not, you will have to use very high quality electric fan/fans with an upgraded electrical feed to them. The factory style clutch/thermal fans with a shroud move a lot of air reliably.