I pulled the Mark 4 engine out of my 89 crew cab. I picked up and 92 2500 last fall and pulled the engine for my 89. This one is a mark 5 with the oil cooler lines built in to the block. I cant find a good answer about just plugging them so im gonna run a cooler. I cant find factory lines so im wondering if I can just use rubber hose and clamps to connect the factory cooler to the fittings? Im worried about the heat from the headers. It would be pretty close to them. I can get fittings and convert the lines to 10 an if they would handle the heat but if i can get away without doing that it would save some money for now. What do you think? Any other options?