No clue on the truck rad. The biggest issue is size, there is not a lot of room in our cars. You can get the dimensions at http://www.jagsthatrun.com/Pages/Parts_DATZ_Radiator_Kit.html.
I tried fitting a 94 Z28 rad from my donor car, wasn't even close. Seems like the JTR manual said somehting about an '86 chevey rad. But the price of JTR's radiator is a deal, its aluminum you get the brackets and fittings and it fits. The LT1 does run backwards. I have the thermostat fitting on the water pump going to the bottom rad fitting on the passenger side and the top fitting of the rad on the driver's side going to the other fitting on the water pump. Do some searching here, you need the fitting for the steam pipe on the LT1 plumbed in or you WILL have major cooling problems. You also need to vent off the air in the heads when you fisrt fire up the LT1 or again you WILL have major coolling issues.