Old horse new beating cam question

stock springs with no dampner they have to be worn out- lots of spring surge
or stock" HP" "red" springs with the dampner
they are dirt cheap
do not even think of a 340 cam especially with no dampner springs
and for get those comp and crane and summit Chevy cams
see if Oregon has a mopar cam
there are good choices from Engle and Mopar performance and even custom crane that have close to stock lift but work much better than el chepo chevy cams
spring for the viton seals
you doing a valve job? cut down the guides for good seals and retainer clearance while you have it apart
what compression?