You say you only want to get to mid/low 11's ?
With a 28" tall tire ? ? , on the 4.10's with a stick, "IF", you want to "USE", and balance, your power & torque for this "ELAPSED TIME" dragrace, you really don't need to spin your 493" inch deal much past the 6000 mark in all 4 gears.
It don't matter what version of the STG VI head you have, you have more than sufficient airflow for THIS criterion, "BOLT ON", untouched. Probably a more "useable" torque curve for the 6000 shift point untouched because of the higher port turbulence/Torque.
I'M NOT SAYING, that any "porting" won't increase flow, IT WILL, just that, unless you're planning on racing in only 3 gears of you're 4 spd., and planning on rev'ing higher, it isn't required. You're not gonna USE it cause you ain't goin there.
Simple formula for your "particular" application;
Assumes flat tappet cam, 10-10.5 C.R., benzene ring(gasoline)
Take your estimated head flow at "peak lift" X .2475 = potential Horsepower that can be supported per cyl X 8 cyl.
We'll leave the rpm/inch factor 'outa this calc., trust me you're OK for the 6000 rpm.
If you can get to 6000 rpm in all 4 gears, AND be doing 6000 in 4 th at the traps, you'll be doing around the 120 mph mark ! With any kind of 60 ft time at all, you're trying for 10's !
NOT LIKELY this will happen, problems with tire/gearing/combo, this IS a street application, not a dedicated drag chassis.
But anyway, back to "Can your heads support the power/torque your targeting" ?
Any version STG VI has gotta flow 280 @ .600". (or more)
280 X .2475 X 8 cyl's means "outa the box" they should support 554 ? Horsepower @ the 6000 rpm mark.
That should be sufficient for your goals in a maximized application(non 3 gear race), dunno how it's gonna work on a 4 spd when you're only using part of 4 th, but should still gain 11's at "whatever" mph.
Bottom line, PORT if you're gonna "go for it", higher than than a 6000 rpm shift point at the strip, mainly the first 3 gears, and cross the traps in 4th at a lower rpm. If you're gonna shift @ 6000, and try to get wherever you can in 4th, they'll work fine the way they are.
Good Luck, hope it helps.