Posted by R.Davis on March 14, 1999 at 21:44:23:
In Reply to: Re: Leaded Gas posted by Vaughn Payton on March 14, 1999 at 13:21:41:
I own 2-64' WM300 PW's w/251 engines,everything I've read and heard about the 60's 251 engine says they are industrial type engines w/hardened exhaust valve seats as is.I use a "S"series tech service manual for 100-600 trucks which includes the WM300.This I believe is for early 60's trucks and states that the 251 has hardened exhaust valve seats which should mean you are good to go as far as burning unleaded fuel,unless someone knows different,I know of no w/you using unleaded.