ok i got a 1991 honda accord i bought from a friend cause he said it was leaking oil way to much i bought it for the engine well now i looked up were the leak was coming from looks like i need a new o-ring between the engine block and the oil cooler (down by the filter area) but i cant seems to find out what to buy and i dont want to take it apart without knowing....were can i get a new one and what size

 

what model? EX/LX?
The intercooler 'O' ring shows to be part number 91316-PT6-003 about $3 list price.

Remove the oil filter and then use a 30mm socket to get the 'pipe' out.

I'd strongly recommend to clean up the threads in the block and the threads on the pipe with some brake clean and use loctite.
I've seen an overtight oil filter cause the pipe to come back out of the block at oil change time.