Just place a piece of card board or thin sheet of plywood in there to protect the radiator. Oil pressure is fine as long as it doesn't cause a leak at the oil filter adaptor ring, add about 10 PSI for every 1k rpm above idle. Usually LA motors should see at least 50 to 60 psi around 3k and above. The P reg will not let it go much higher unless a H p pump is installed which is only set by the P reg spring in the pump. H Vol pumps have larger cases and gears but usually set P around stock and will show slightly higher P at rpm, then you can get H p H V pumps but as I said, watch out for leaks at the oil filter adaptor. Using a cast adaptor will make for insurance here, the stamped plate is a POS it will promise to blow out and empty your pan for sure if you raise the P. The whole reason for big pumps is for when the engine is built sometimes bearing clearances are opened up especially the side clearance of the rods which will lower Pressure and increase flow to cool the crank journals. A stock pump will not supply enough to maintain pressure here until the rpm come up and it will still be lower than it should be in most cases. For instance engines that have the pump in the front cover casting, a spacer must be used to install a HV pump, the only thing you can do without the spacer is raise the Pressure, open up oil passages so more can pass through which essentially does give a little increase in volume and decent increase in pressure. Old AMC, Buick, and 3.8l GM are some examples. All old MOPARs use either an external pump, slant 6 and BB or in LA, in the pan, like SBC's and Fords. Everyone went to direct drive on the crank snout to reduce parts. This has become a problem as the housings are made of cast Alum and they wear causing loss of pressure when the oil warms, the pump expands making the problem even worse. So much for improving quality.
