Tom, TJ posted a link to one of the synthetics companies recommending that our flat tappet engines run their 15w50. So you're weight choice is correct. However I would suggest you try Mobil one,Redline or other full synthetic for one period. The synthetics can help cut through some of the stuff that you think may be built up in the returns. Also. I have seen oil rings stick and the synthetics will help in some cases. I'd use a castrol pure one filter (just my preference) and swap it out at 1500 miles or so. Keep an eye out for pressure drops during this. It is remotely possible the screen could plug. Some engines I have put synthetics in seem to have zero change. Some it helps. Other than speeding up the rear main drip on the 97 I have never had a negative result. The drip slowed back down by going back to standard oil. Sent from my BlackBerry® wireless device from U.S. Cellular -----Original Message----- From: "Tom" <tnmorrison@xxxxxxxxxxxxx> Sender: amc-list-bounces@xxxxxxxxxxxx Date: Fri, 20 Aug 2010 14:15:04 To: <amc-list@xxxxxxxxxxxx> Reply-To: Tom <tnmorrison@xxxxxxxxxxxxx>, "AMC, Rambler, Nash, Jeep and family" <amc-list@xxxxxxxxxxxx> Subject: [AMC-list] Home again(some more) I didn't do a Nutter bypass, and I'm currently running 15W-40 diesel grade oil(for the zinc). I don't do much of my own work(got enough on my plate!) and finding "willing" mechanics in this area has always been problematic. I'm the ONLY AMC owner in my town, and my SX/4 seems to be the only one around that I ever see, though I know at least one Spirit owner one town over. It's sort of lonely... -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://list.amc-list.com/pipermail/amc-list-amc-list.com/attachments/20100820/d5f56b13/attachment.htm> _______________________________________________ AMC-list mailing list AMC-list@xxxxxxxxxxxx http://list.amc-list.com/listinfo.cgi/amc-list-amc-list.com _______________________________________________ AMC-list mailing list AMC-list@xxxxxxxxxxxx http://list.amc-list.com/listinfo.cgi/amc-list-amc-list.com