Well, in a not very scientific mileage test today I drove from Sumter, SC to Summerfield, FL down I-95 and then US 301. On I-95 I started out gently doing 60's and let the coach find it's own way. Not long after the Santee bridge I had to keep telling myself that it's an old engine and you need to keep it down to a dull roar. 3100 rpm is 70 but I like to keep it at 28-2900 on the interstate. Keeping the manifold gauge in the green is the key.
Mid point fuel stop had the coach doing 8.5666666 mpg.
Now that's with headers, MSD ignition though not variable timing...kinda flat here anyway, oh and the cold air intake from the front via the big hose.
I need to find the time and patience to cruise up the same way at 25-2600 rpm to see what kind of savings I can expect with the GearVendors.
Oh, gas at the start was $1.539 in Sumter at Wally World. Gas here in Belleview FL is at $1.599.
1984 28' Funeral Coach
Former Rolling Showroom & PuttLab (now party bus)
"I'm not an expert. But I did sleep in an Airstream last night."