Money no object Hmmmm! Want to build my motor then
Just kidding
Seen as u got a decent budget first I'd think conversions. V8's make better power & tourque dollar for dollar than a six. Windsor wet wieght not much heavier at all than u're six. Cleveland cheaper to source parts for.
Or if you're really into sixes or can't leagely convert to V8 where u are consider a later six price a new BA engine agianst bombing the crap out of a X flow to get the same performace but no fuel economy & reduced reliability price a BA XR 6 turbo engine against turboing & up grading a Xflow to cope. Even an EF engine would make a much better starting bed especailly since u'll be able to aford quility engine managment bits.
But if it's gotta be Xflow (I'd first suggest finding your self a clean TF cortina as a base instead of a falcon??) back too the cross flow: first top end if u got money to burn boost is where its at *TURBO* it port head fit bigger valves mod for screw in studs /guide plates/roller rockers/quality retainers collets/valve springs/ machine head for triple valve springs incase u need em go to town!! O.ring seal head to block use stud kit becarfull of No1 head stud many people brake the block out there. Carb combo or injection up to u're budget, inter coolers blow offs the hole nine yards. Need mapable ignition system.
If its gotta be naturally ass there a DOHC multi valve alloy head made in small volumes for these engines GET ONE! port the crap out of it match port manifold run big tripple webber side draft carbs 45's or 48's depending on head flow, cams to suit & run custom build extractors & 2 1/2inch exhaust all mandrel bent.
Bottom end (for either top end just change deck hieghts & copression ratio's to suit) first make sure u got block with one piece neopreme seal. the get it bored & sleved (there a bit thin in the bores other wise) machined for O'ring head seals & have the cam tunnel line bored & the crank tunnel machined to aceppt a EF crank & a stud kit. gear drive the cam, with a good budget have a steel crank made to EF spec & lightened,use titanium rods & rod bolts at either 200 x flow lenght or longer with custom rods & pistons. Use top quility pistons & rings of u're brand chiose. Have the inside of the block deburred & polished for better oil flow, fit oil restrictors ect
Hell I could go on all night its only you're budget that limits the possable performance gains for any engine so becarfull when u say money is no object
But that's a quick out line of some possable combo's for good budgets but of cause there'll be heaps other's out there too so waist the time to do a lot of research first before u spend anything. Espacially look for people or engine rebuilders that have lots of experiance with using these engine in some form of high performace motorsport. hope that helps a little