Comp-Cams makes a 'damn nice' kit.
XE-268H ~ {#20-223-8}
Lift.......................... .477"/.480" Lift
Duration.................. 268*/280* Duration
Duration @ .050" .... 224*/230*
LSA......................... 110*
Overlap................... 54*
Valve Springs ~ {#VS-901}
Type....................... Single Coil w/Damper
Valve Closed........... #101 lbs.
Valve Open............. #242 lbs.
RPM Range............. 1600 to 5800
The 54* Overlap works well for a 'Hot Street Performance' 340.
And the Valve Springs are 'not' over Load-Rated, which doesn't beat up the Valves and Valve Seats.
Note; We installed over 300 of these kits in 'Street Performance' Mopar 340's , and not a single complaint.