What engine are you running? If a standard engine and not a 20v turbo you should be fine with the size of the radiator fitted, if the cars getting hot it may be your current radiator is old and blocked up. Old coolant will also not help with cooling.
I've hammered mine down the motorway, got stuck in traffic for some time in hot wether and the temputure gauge never goes above 3/4 when stationary then the fan kicks in and back down to 1/2. When moving it sits at 1/2 way.
Mk1 78 Scirocco GLS 1.6 FR, weekend toy.
Mk1 88 Golf GTi cabriolet 1.8 DX. Daily drive.
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