[Amps] Water cooling heat exchanger approaches

[Dfmich at aol.com]

Hi there

I am working on the water cooling apparatus for a N6CA 1/4 KW 23 cm amp. In 
his article, he talks of using a "small transmission oil cooler" for the heat 
exchanging function. Does anyone that has done this before have any more 
specific descriptions than this; ie, a cooler from a 19xx Ford whatever or ...... 
Are there any other sorts of approaches to this heat exchanging function, even 
homebrew ones?

Thanks 
Dan K9EA