Stock internal 318 redline??

I had my 1st 68 dart 270 318 650 vs 727 3.23sg headers 2 1/2 exhaust g-60-14 5500 drive atleast 50 times woudnt pull any farther
after 5300 it took for days
that was before 2.02 340 heads and the street hemi cam i was still scared to rev it over 6200
i let someone run it down the street so i could listen my brother said he tached it to 7k in 1st dont think so with stock 340 red stripe springs
it sounded real good either way