So Ive found that my valve stem seals are bad, do I need to pull the head if I add air preasure to the cylnder to keep the valves seated? and while I'm under there, and I put in a hotter cam, springs, rockers ect... would I need to tune my afm or anything elese? Thank you!

 

You can use compressed air if your valves are not too leaky. You can also use the rope trick.

 

my compression is top notch, the rebuild only has 60k on it. whats the rope trick?

 

Get down to your bare valve springs.
Take a peice of rope that will fit into your sparkplug hole. Wad it up to get an idea of how much you will need to fill about an 1/8 - 1/4 of the volume of your cylinder. Bring the piston to BDC (or there abouts) comming up on the compression stroke. Push the rope into the hole leaving about foot hanging out( dont want it to fall all the way in). Continue on up toward TDC( the piston will compress the rope and push on the valves) untill you cant move the crank any further( east does it). You can then compress and remove your valve springs without the valves dropping into the cylinders.

Works well, have done it many times on aircraft engines and a few on car/trucks.

This being an interference engine, you may just be able to bring your piston to TDC and pull the springs and not have to worry about the valves falling in( it depends if both intake and exhaust valves interfere).

I have droped valves down into the cylinders , so I could ream the carbon out of the valve guides and then picked them up through the guide with a magnet( not for the faint of heart , but after a few times its easy).