you have to search for engine parts/costs in your area,,,
049 headsor better,ported. 225 intake valves and 1.88 exhaust valves
850 Holley or better
headers like Hooker Competition series
cam like this
120605-12 CL120605-12 286 300 233º 247º .600 .612 112 108 Hyd.
2500-6200 Mild idle, Hot Street. Great mid range performance. 9.5:1+ CR, 2500+ stall.
go 9.5:1 compression for GM cast heads
If you buy better aluminum heads then make CR 10.3:1
Used LS-5 or look for a short block and buy what ever heads you want.They need to flow 300 CFM
machine work including balancing,squaring,decking,and custom fitting the pistons,(maybe machining pistons for valve clearance
Heads will be $1200-1500 with porting and installing bigger valves.
Cam and kit over $1,000
rings bearings,timing chain,Gaskets, misc. fastners
good ignition system with rev limiter
Holley HP $600.oo custom built
fuel pump and regulator
the big block swap.. unless you buy a complete 454 fully dressed, meaning with the alt/ps pump/water pump/ ac compressor and all the brackets and pulleys.. list like above are , well in my eyes a waste of time..
no idea where you are at.. but scope out ebay and craigs list/et for 73-87 trucks with a big block in it.. there are many that are running but the body is rotting off them.. this is the way to go.. if on a budget.. as that rot box will supply you with the frame stands for a big block (I know the 67-72 are different small block to big block and my guess is the 73-87 are the same deal as the frame didn't change enough..(the front engine crossmember bolts into a 60 or 62 through 72 truck (you can sell this to owners of 70 back truck owners that want disc brakes to make part of your big block buy in less) you also get the correct radiator and fan shroud,fan/clutch, the radiator might be junk but at least you'll have something to match a new one to..
you'll get the front dress brackets and pulleys and alt/pspump/etc even if they are used just for core charges (alt,ac compressor,starter) it can knock 100-200 off your engine swap cost..
If you are lucky it'll have a hydra boost brake booster.. it'll need new seals but now you don't need to worry about vacuum for your power brakes you can go as wild on the cam as your heart desires.. and if 2wd you got a th400 trans to back the 454 if you don't go overdrive right off the bat..
then you part the rest.. and scrap the left overs and have got the 454 for FREE.. and a bunch of extra parts for your 84..
NOW you can dream up the cost of building your bigblock..
buying a short block or long block and not having the frame stands and assessor front dress.. can cost you more in the long run, than if you got a running rot box and pulled the 454 and scraped the rest..
I got lucky the yard a mile from me had a 84-6 dually with a 454 in it.. and got the engine fully dressed.. oil pan to air cleaner flexplate to fan (alt/ps pump/frame brackets/new starter the works)for 800.oo
and opened it up and it looked to good for the miles on the truck.. so I went back to buy the th400 and it was already gone.. but the glove box had the receipt for the replacement g.m. new long block and was dated 4 months before I bought the engine so it's basicly new.. wish I found the receipt before I unbolted the whole works.. but..