Regarding the cold start issue, search for a thread started by me about a year ago "fuel accumulator failure analysis," and run the simple test to check yours. The cold start injector valve is not activated unless the ambient temp is below about 32F.

Chances are the radiator has a lot of built up deposits if antifreeze changes have been inadequate or "green" antifreeze has been used, which can cause a lot of deposit buildup due to all the silicates. These deposits are insulators and will drastically reduce heat transfer.

There are some shops that claim they can remove the plastic side tanks, rod out the aluminum core, and then install new plastic side tanks and seals with no leaks, but you are probably better off in the long run buying a new Behr radiator. If it's the OE radiator the side tank seals will eventually leak and the hot side nipple has been known to break off when changing hoses or even driving down the road. Radiators don't last forever and getting 26 years out of an original is not bad.

Use Zerex G-05, which is the original BASF patented HOAT blend that was OE in that era - a 50/50 blend with distilled water, and change it at least every five years regardless of mileage.

Duke