mopar performance red valve springs with stock 340 camshaft

The DC/MP part# is P4120249, a direct replacement for the H.P.340 unit, p/n 2863439.
Spec. is 70# minimum at stk. installed ht.,
260# at .500" lift, rate is 386#/inch.
The 901 Comp spring specs are;
~90# minimum at stk. installed ht.,
260# at .500" lift, rate is 353#/inch.
The key with the Mopar units is to be sure the installed hts. are tight enough to achieve the seat load of 70-75#, shimming if needed. If those springs haven't gotten rusty or run overheated, & pass the load check they'll be fine. The Comps having a longer wire with less rate offer more seat load, by about 20#, for what You're doing either is fine.