Airboat with SBC 3970010

[Swamp Barbie]

I have a SBC 3970010 with K0424TDJ K7 stamps. I am trying to figure out year and make info so I can order a new spring. This engine sat for 12 years and have 52 psi on one cylinder. Any help is appreciated.

 

[hurst01]

When you did the compression test was it wet or dry? Could determine if indeed you do need a spring or not.
Just curious, how did you determine it was a spring problem?