i just bought a 99 dodge 2500 with a 360 v8 in it and ive put about 500 miles on it. i fired it up this morning no problems other than it blew some white smoke for about 10 seconds i drove down the road and noticed my brake pedal had one from kind of spongy to super stiff but it stopped fine then i didnt have the power i should and could almost watch my fuel gauge drop. i have no ideas any help would be much appriciated

Brakes dragging.

Clogged Cat. (from blown plenum)

Failing O2 sensor.

Or any combination of the above.

thanx i also noticed it used a quart and a half of oil in that time

Yep, plenum for starters... Read the stickied thread at the top of this forum for some pointers there.

i appreciate the help