Changing Push Rod Tubes

Leakage seen from pushrod tubes (and flywheel seal)
how can i replace the tubes without dropping the engine?
and how much does a stock tube costs?
OOT: how about flywheel seal?can i do anything to prevent the leakage from there?:banghead::banghead::banghead:

The only way to stop the leak is to pull the engine and replace the main seal.

As far as the push-rod tubes, you can get the spring loaded ones, that you can install just by loosening the rocker arms and turning them out of the way. You can then remove the push rods, pull out the old tubes, clean the seating surfaces and putting the new tubes in. Then just re-install the rods, swing the rocker arms back and go through the valve adjustment process.

http://www2.cip1.com/SearchResults.asp?Search=push+rod+tubes&Search1=Search