I have a 403 installed finally into a 1977 Silverado, which has a leaking frost plug on the passenger side cyl head, how tough are these to change, Ive never done one before, any ideas?
Thanks
Al

 

Being on the head, it should not be that bad. I am assuming you have plenty of room to work since it is in a truck. What I would do is take a brass punch or something else that won, punch through the freeze plug and try to hit it so it flips the plug sideways so you can grab it with some pliers and pull it out. Try not to knock it all the way in the head. Use a brass plug to replace it.

 

Took some doing but I got the old one out and picked up a expansion type from the local parts store, should be good to go!!