Do you know how many miles are on the motor? If it's in that good of shape I would leave the bottom end alone and focus on the top. $3k budget?

440 Source heads: $1k
Used dual plane: $120
Headers: $150
Used Holley: $150
Cam set: $150
Rear sump pan: $150
Mounts: $100
Gaskets: $100

I know you said you weren't considering aluminum heads, but after freshening up a set of irons you're halfway there and you still need to deal with the compression issue.