340 valvetrain help

Wow 25 initial is allot. Was the vacuum advance disconnected.
Depending on your engine build 25 initial could be correct.
42 total with vacum advance is also not out of line.
I would try less 18 initial 18 mechanical for 32 plus vacuum advance.
Slow down your curve with heavier springs to have timing all in by a 3400 rpm.
It's a tuning thing could take a while.
If you give details of you engine people could recommend a more accurate
base tune to start with.