what i and others on here think is that by adding a johnson cm30 to your system will not affect the i/c.
to reduce temps with the pump you will also need a larger h/e ie: the let or supercooler or custom made unit.
also isolating the i/c coolant from the engine coolant will have an effect on reducing temps in the i/c
i personally have the johnson cm30 on my car without any other mods and have seen no issues with the i/c. as funds allow i will upgrade the h/e and isolate the system. the reason i used the cm30 is that the stock pumps have a history of failure.
wally care to add anything?