gotta brougham with a 5.0 liter 305. im loosing oil, NO leaks, white smoke when i start up, my coolant level is fine, im not loosing any. im hearing it the valve seals, how hard is it to change em yourself in a driveway? i looked in the Haynes manual , and it looks like a pain in the ass. said u gotta stuff the cylinders with rags:banghead: and use air so the valves dont fall in, and also said u gota turn the motor as u change them. is there any way to do it with out turning the motor, etc??? thanks for ur help by the way..

The book is correct except for the rag. Each piston is brought to top dead center, then an air hose is screwed into the spark plug hole and air is pumped in to hold the valve shut. Then a special tool is placed over the valve stem once the rocker arm is removed. Remove the spring then the seal. Replace spring and rocker arm. Once all eight are done then you must adjust all the rockers like an old V/8 Chevy. most times the failed seals are the intake valves only. So most people only replace those. Good luck!

Spend $500 and toss on a pair of Vortec 350 heads..... :)