Trick flow 240 or 270 for 421 big block

Hey all! Im new to this site and thanks for having me!
Ive got a 421 short block consisting of: a 72 cold weather 400 block .040 over, half filled, studded mains, bushed lifter bores. 3.5" stroke offset ground 383 crank, 2.2 bbc rod journals. 6.535" manley i beams with .990 wrist pin. And 1.695 ch ross forged -14 cc dome pistons. Ive got an old rr-660 isky solid roller in it right now.
.660 lift int + exh
.324 adv. Duration int+exh
108 lsa.
My question is i cant decide on a set of heads for this thing. Id like to either go with the trick flow 240s or the 270s
This combo will be going in a 3200lb 72 duster, ss springs on a narrowed and back braced 83/4 with 4:30 gears.
904 tranny with a j+w big block bell, 1:74 first gear and a 4500 stall ptc 9.5" converter.
Any help and suggestions is greatly appreciated!