The RS500 intercooler fits in the exact same spot as a standard 2wd one, but it has longer tubes and hangs in FRONT of the rad correct? The mounting tabs mid end tank mount up with a bracket to the rad correct?

 

The RS500 type intercooler is indeed in front of the rad, and about another 1/3 in height, going all the way to the top, and yes it has much longer pipes, from memory about 5"-6" long.
I am not sure how a genuine RS500 cooler is mounted, other than the through bolts that go upwards through the box section of chassis, which is the ONLY mounting on most aftermarket RS500 type ones, I fitted a piece of rubber between my rad and intercooloer because of the rocking, then tie wrapped it with a tie around the n/s outlet pipe and headlamp shell back piece to stop it moving.
tabetha

 

Correct Tab - the top side has two angled brackets that have 'cotton reel' rubber mounts that bolt to the top of the front panel. One is kinda bent because it fits around the air intake.