Not exactly a science lab test but,
I drove out from Vancouver Island to Alberta and return three years ago and did another trip this month. Both trips were about 3000 miles. Went to Calgary and did day trips from there. Not exactly, but close to the same trip. Same carb and carb tuning, tranny, rear gear, tires, etc. First trip I had my wife with me and her trunk full of luggage, second trip alone but more beer in trunk. Probably 130 pounds lighter the second trip. Only real change was the camshaft and lifters.

Camshaft specs:

Trip one:
Duration at 0.006 - 286/289;
Duration at 0.050 - 230/236;
Gross valve lift - 0.565/0.570;
Lobe lift - 0.3770/0.3800
Lobe separation angle - 112.0;
Intake centerline - 108.0 degrees
.
Trip two:
Duration at 0.006 - 289/306;
Duration at 0.050 - 236/245;
Gross valve lift - 0.570/0.574;
Lobe lift - 0.3800/0.3830;
Lobe separation angle - 112;
Intake centerline - 108.0 degrees.

Lifters:
Trip one - Hydraulic roller lifters;
Trip two - Solid roller lifters.

Gas mileage:
Trip one - 24MPG;
Trip two - 20.8 MPG.

Almost all highway driving was at 70 MPH, faster when passing, except on the Coca Cola highway which was 80 MPH, faster passing.

I'd be tempted to remove the camshaft and replace it with the trip one cam, and redo the trip, but I'm sick and tired of wrenching on the thing.

No question just thought I'd put this out for interest sake.