hey I am new to big blocks and have a couple of questions. I have heard that running 15w40 diesel oil will make the engine last longer is this true? i have a 2000 gmc k2500 with a 454 in it (I am not looking to make tons of horse power). also I was told that it is ok to plug the oil cooler ports that are next to the oil filter. is this ok to do? the reason for wanting to plug them is that I spun a rod bearing and I am in the middle of the re-build if I cannot plug the cooler ports I will need to run a after market cooler so I dont get the old oil that has bearing crap in it in the nice clean block and I dont tow mutch. I would like to save the money if I can plug the cooler ports. thanks for all the help!!!!