Solved mileage and power problem
Solved a problem and thought to share.
I bought my 345 with gas 454 last year. In prep for a 3,000 mile road trip home, I had some mechanics do some basic maintenance and upgrades. Mufflers were shot. So, I had them install a banks power pack.
Trip went well except for swapping a lot of rear fuel filters every time I'd climb a western grade or cross a railroad track...sediment. However, I got crap mileage, ~5mpg, and it was REALLY slow going up grades.
So, power problem got worse after I got it back. I'm looking at fuel system, carb tuning, etc. didn't have time to wrench. So, I brought it to the mechanic.
It turns out that the mechanics didn't put spark plug wires properly back in loom after replacing headers and muffler. The heat from the headers melted 3 wires as they were just laying on the bare metal. I had been running on 5 cylinders for ages.
Of course, now that I'm back on 8 cylinders, this thing is quick!