I have a mix match of parts from a couple of '87's. My parts car is an automatic and has the coolant overflow line and fill cap on the thermostat housing. The radiator that's currently in my car has a coolant overflow line, with fill cap on the radiator.

My question is: which is best for bleeding air from the cooling system or do they both work fine? Thanks ~rich

 

the highest one of course..

 

The one that has a plastic bleed screw that you can take out without destroying the threads.

 

my 86 used both, original radiator newer water pump and housing. use the higher one, helps bleed the system