things needed for cam swap

[6.0vortecchevy]

is there anoter way to hold the valves up besides air? its what i used when i did my cam but im about to change cams and dont have an air compressor this time. any ideas?

Or you could use the top dead center method, its works ok but some times its a pain since the valve drops a little before it hits the piston and it makes getting the spring off a little harder.