Radiator recommendations

I am looking for some radiator selection advice. The car is a 72 Scamp 318 (with working AC) 4bbl, dual exh, 3.55 rear, currently with factory 26" radiator and AC condenser out front. Right now the temp climbs on the freeway after extended driving (30-40 mins sustained speed) indicating a clogged radiator. I have flushed several times and made some difference but IMO it shouldn't warm up how it does. It never goes over 200ish while cruising but I want it to work correctly. Timing is set correctly, fan works (clutch fan) and the temp comes right down after I slow down.

I want a radiator that can:

1. Handle AC use in heat
2. Handle LA traffic
3. Handle some mountain driving
5. Handle 105 temps on occasion (mostly operating in 90s or below though). no cold temps here the last few years. seems to be in the 80s all winter these days.

I am considering the champion 26" 3 core (CC374), I know they have some QC issues. Is this radiator still A body friendly? I read somewhere it might not be anymore.

Hoping with my current 26" in place it means i won't have to modify much to make it fit. Another concern is that I want to keep the clutch fan if possible, will my 26" factory shroud would work with this? If possible i would like to avoid the hassle / cost of electric fans. Would I be ok without a shroud if it came to that?

Any guidance is appreciated.