i know, i might as well just leave this website! Forget it ! if im just going to givin smart anwser's.
you want a 6 to sound like an 8 for free and you were given options...
if ya wanna spend some coin do this :
ok :TOP END: port & polish head and manifold match a cain 4brl with a 600 holley vac secondary(modded butterfly) and some extractors(1 & 3/4 inch primary and get them matched too), 2 and a half inch single system with a hi-flow muffler - 3 inch from the dif back, oversized chev stainless valves, titanium valve springs, roller rockers, multi point plugs, 10 mm leads with standard electronic dizzy (with the plastic gear removed and a steel one replacing it, cos at 7 grand they tend to break) oh my head was flow tested to handle 350+ horses
BOTTOM END: i had a steel crank (HP block) but get urs balanced, lightened, bored .040 acl flat top with acl rings/bearings is fine, 32/74 XU1 spec CE 631??? cam (Hydraulic), run straight cut steel timing gears, balanced balancer (not lightened - if anything get a heavier romac) shaved and balanced flywheel, heavy duty clutch behind an M20 (make sure u weld up the shifter good cos these break under abuse).
had the same setup in my VK wagon years ago with a 179 HPblock dynod 146 horses and always got asked to "pop the hood....thats not a 6" by other enthusiasts and police. RIP Anzac Avenue Redcliffe