powerglide decode

[68c10]

can someone please help me decode a powerglide i just bought. there were no casting numbers on the main case only the tailshaft housing and the tranny pan here are the numbers
tailshaft 3789080
pan c0418d
also there are 2 holes about 2.5" around on each side of the bellhousing area i was told it was air cooled is this true? there are also 2 plug were it looks like a tranny cooler should go can i hook up a cooler to those? please help

[JohnZ]

That transmission was made at the Cleveland transmission plant, which only made Powerglides for 4-cylinder, 6-cylinder, and 283 V-8's. The air-cooled aluminum Powerglides were only used on the Chevy II and the Vega. The rest of the code says it was made on April 18th, day shift.