Im looking at a boat that orignally had 400 cyclones. Its a 1983. It now has 420's. The thing is, I dont think I noticed any external oil coolers. I noticed the oil lines goes from the block to the oil filter adapter. Am I missing something? I knew the 454mag/bravo had the oil/ps cooler on the port side of the block, this one doesnt. Could someone have replaced the engines and not put the oil coolers back on?

A lot of the old engines had oil coolers (tranny & engine) built into the bell housing. Check to see if your raw water hose connects to the bell housing from the water pump. It should also have oil lines that go to it from the engine and tranny.
If not, someone left off the external cooler. Not a good thing on that engine.
Gary

Ill check today. Thanks Gary

those were usually a 420/trs package , so the boat should have a transmission , the coolers will be in the bellhousing , port will cool the engine , starboard will cool the transmission.

pic of what housing may look like