Hi I just bought a restored Allis-Chalmers D17 IV GAS tractor that was made back in 1967. The operators manual calls for 10w30 engine oil. They do offer a description- "Your tractor engine should be provided with MS oil. Oil designated MS contains certain additives to increase film strengh, to be corrosion resistant, to carry contamination in suspension, and as pour point depreeants, etc." The working RPM of this engine is 1650 and it is a 226 cu. in. 4 cylinder w/56 pto hp. What would you guys recommend?