Classic/Antique Car Repair: valvespring replacement, valve job, valve springs

Question
Hi i have a 1977 403 olsdsmobile motor. I want to put new valve springs in it. Can i do that without taking the heads off.

Answer
HI;
   Moon;
        There are ways you can do it on the car, I did it a few times on my chevy when I broke a spring but I do not  
like doing it on the car,  you can get a air tool that you place in the spark plug hole - first you remove the plug than screw in the tool and put air pressure into the cyld. but if you loose the pressure or the tool comes loose you will have to take the head off. so you must be carefull
if you need valve springs I would do a valve job also , but yes  you can replace the springs on the motor w/o taking the heads off it can be done on the car. with caution.