It took you years to figure out what makes'em tick for better mileage? When I read on, below, I can not for the life of me believe what I read.
The difference in adhusting my 360 in a 4000lbs car was less.
OE parts were reused. twin cats on a new exhaust that followed the pattern of the OE dual exhaust and I added weight to the car with more sound deadener, 2 amps and a sub woffer. OH, a real spare tire over the colapsed donut.
I'm sorry fellas, I think that the constant 19 - 20 mpg's out of a V8 with twice the power and torque is well worth the dumping of the slant 6 hands down. Adding the MSD was also a mileage getter with an extra 2 mpg's on a solid every time any time bassis.
This car also started off as a 10 mpg Hwy. car that did still sport that catastrphy of an ignition, the "Lean Burn" which was tossed in favor of the old Orange box set up that the dealers used to carry in stock because the lean burns were so bad. This ignition swap was standard pratice. So don't bother running some crazy crap up the tree on me for the swap.