[b-man]

By staying with the 15-1/2” core support you limited yourself to not only the smaller radiator with 1” tubes instead of 1-1/4” tubes but you’re also missing out on the larger 19-1/2” fan.

If you want the additional peace of mind and cooling capacity of the bigger more efficient large tube radiator and 19-1/2” fan plan on spending whatever it takes to replace or modify your core support and upgrade your cooling system.

It’s not a big deal finding out what your upper limit might be, don’t be shutting it off at 197 let it hit 220 before you shut it down next time. 20 minutes sitting in traffic with the air conditioner running and only hitting 197 seems like you’re doing fine to me.