"Good points. I wondered about copper expansion at first, but this bushing is considerably thicker than standard copper pipe and I don't think it will expand a great deal."

- The expansion coefficient of copper is the same regardless of its thickness. It is the temperature differential that controls the degree of expansion. It doesn't really matter anyway since the expansion coefficient of plastic is greater than that of copper.

"The coolant corrosion issue is one of interest, and I hope some chemical expert (or near expert) here might offer an opinion."

- Until the early 80's radiators used to be made out of... copper.

- The best way to maximize the lifespan of an original radiator is to leave it alone. Over time plastic hardens and becomes brittle. Messing with it can only lead to premature failure.

__________________
Reno

'93 300E 4Matic
'98 Nissan Altima
'00 Yamaha Road Star Silverado