PackardV8 wrote:Hi, n2omike,
Just for the sake of discussion, what factors would cause a performance-built 750 CFM Edelbrock 383" to get better mileage than a stock Quadrajet 350"? I'll take the bet it won't, assuming an equal condition and tune.
thnx, jack vines
The Q-jet is set up just like the factory built it in 1976... so I'd say the tuning could use a lot of help. 12mpg, driving easy, isn't that good... so there's a lot of room for improvement. I'm not expert at tuning the Q-jet, but the Edelbrock is easy. Add in the LM1 to get the the cruise, etc just right...
Thing is, if I build a new engine, a 383 crank is only a few extra bucks, and those extra cubes will come in handy when towing. The Vortec heads are also a no-breainer... especially when feeding the extra cubes. Getting them off a junkyard engine, and getting all the required parts... head bolts, pushrods, rockers, etc, makes them a great deal. No sense in building an old-headed 350.
I'm not comparing both engines, all else being equal. I'm comparing a STOCK 350 Q-jet with factory tuning to a Vortec headed 383 with a LM1 tuned Edelbrock carb. I would think the 383 could be built to run circles around the old engine, and still get better mileage... Just more efficient, overall.
The old engine also has 146k miles, but still runs good, even though it uses a little oil.
Cams? I'm aware the 108 LSA will pump up the midrange, but will it also kill off 2-3 mpg?