26" radiator for a slant six?

Hello guys

My '71 Demon doesn't have its original radiator anymore, but a brand new aftermarket one.
Cooling is just fine.

I have the opportunity to buy an original but used 26" rad (#34434970), seemingly for '71 318/340. Isn't it too much large for a 198ci, causing too much cooling?
Would the cooling liquid reach 180°?

Thank you in advance
François