i need one...i think i saw it at brandons awhile ago...it might be too small for my 14qt pan....i am getting into the 250+ degree range with my oil 
B-rad, the oil coolers are based on oil flow, not volume. Simple math says your oil temp was only a little warm (I like 200-225*f as a guideline) and you need a minimal cooler, that looks like a King Cobra OMC oil cooler from a 460 Ford I/O, could be wrong.
I actually make these and other heat exchangers at home as sort of a hobby, not necessarily for resale (more like Christmas gifts
).
You will need about 30 square inches of cooler surface to drop the oil temp about 40*F with a normal jet pump flow of 65*F water (I could explain where the math comes from, but it's involved and boring as shit). The cooler shown has quite a bit more than that, but are "non-serviceable" and somewhat restrictive for a racing application, non serviceable meaning you cannot access the "oil side" only the water side, so if it gets contaminated, cannot be cleaned properly.
My funny suspicion would be that your oil temp would have gotten a lot hotter had the hull not been full of "coolant"
In short, 250*F does not scare me too much, but will get a hell of a lot hotter on a hot day and in warmer waters, so you need to do something....
GT
