i have a 1985 s-10 blazer that i put a 267 v8 out of a 79 malibu into. i am having trouble getting my timing set as too every reference i look up gives me different specs. i am curious at to what the actual spec for the 267 in 1979 would be and also what end of the vacuum hose do i plug off when i remove it from the vacuum advance to set timing. my goal with the truck is to optimize mpg rather than power and speed. i recently installed a summit ignition box and lost about 2 mpg which i dont quite understand why. i put the condensor back in and am going to run some tests to see if this improves my mpg. i have installed new plugs,wires,coil,cap,rotor,fuel filter,fuel pump, and i intend on droping from a 650 cfm carb to 500 cfm. i would like to reinstall the ignition box but not if its going to decrease fuel economy(which i was told would actualy increase mpg). after installing all the new parts and making adjustments i actually lost mpg which i find rather odd because through the mountains on my trip down i was getting better mpg than i did once i hit the flatlands. i am rather confused by all this atm so any advise you may be able to offer would be greatly appreaciated.