I'm afraid that the only thing I can say about oil is don't put synthetic oil in a newly rebuilt engine. IT leaks all over the place! ----- Original Message ----- From: Denis Dodson To: tcb@xxxxxxxxxxxxx Sent: Friday, August 12, 2005 7:59 AM Subject: [tcb] Tech talk Does anybody believe that the 412 ring and pinion transmission is better than the Freeway Flyer in the cooling areas? The Freeway flier is said to run too low in the RPMs to allow very good cooling at high speeds. I usually run at around 150 degrees at 65 MPH (I run a remote cooler) I also have been told that the viscosity of my 20-50 will not work well at lower temps. Also my lower profile tires cause my speedometer to read off by 1.25 more then after 1000 miles how inaccurte is my mileage counter?