I have a pulsar radiator in my ute (A15) and it does a reasonable job, but it creeps up in traffic. Without a proper fan shroud this will probably happen whatever you put in, just cos the flow is not correct. thermo's will fix the prob though. Also make sure you have the right water pump. some (all?) of the A-15 ones have a shorter shaft and a smaller pulley diameter (i.e. run faster)