My 360 Magnum is sick

Poor motor is coughing and sputtering. Problem started over a month ago. On a Thursday night test and tune, last run of the night during a burn out, the motor back fired. Should of known them but I ran it anyways and it coughed and sputtered down the eight mile. I had been having some ignition problems and had already decided to switch over to a complete MSD ignition system. So I drove it 20 miles home. This all happened the week prior to the local Summit race on Sunday.

So as usual I waited till early Sunday morning to switch over the ignition and had some problems. I did get them straighten out and made the race that day. Only problem was the car was still sick. Went out first round against the series leader and drove it home. Been dreading working on it for the last three or four weeks and the car has just been sitting while I work on other less important projects.

Tonight I figured I better look at it as next Sunday is the next summit race. Here is what I found. Looks like I broke a valve spring. I'm pretty sure that is not a big deal. I've heard you can pressurize the cylinder and change them. Sounds easy, anybody have tips, tricks, or methods. For doing this work. Will be my first time messing with the springs. I usually leave valve work to the machine shop.