This seems like a topic that comes up often! One thing to watch is the specifications, including and especially the lower cost brass/copper replacements. I had this problem on a '78 PU. 3 core "extra cooling" parts store copper/brass radiator and she would warm up on a hard pull in hot weather. On a roll. Those rows were thin.

The other is cost. A factory style radiator built or re-cored with a 3 or 4 row high efficiency brass core should cool great. Also not cheap. Same comment on a higher end aluminum unit. They cool great but are not cheap.

The pickup (brand F) got a 4 core Champion. The stock shroud fit and it cools much better than the parts store brass unit.

My stroker BB with AC runs a higher end aluminum radiator (Mancini Muscle Car radiator). Stock mounting, stock hoses and made to order shroud. Cooled great for 10 years, including stop and go in Las Vegas, until a super single gator took it out. I got another.

For the OP, a 3 core Champion may do the trick if they make one for that application. A Mancini or Griffin radiator made to spec should work great. A high end copper/brass unit (Glen Ray I believe) would certainly do it. Personally, in that application, I would try the Champion. If you want to be really sure, the Glen Ray, Mancini or Griffin.