With a heavy street-driven vehicle, you will want tons of torque, not necessarily a lot of hp. Here's a recipe that I worked up on the DynoSim software a couple of years ago that may be of interest.....this is a pump gas-friendly build.....
400 block bored 0.030" and zero decked to the piston crowns, align-honed or align-bored main bearing bore.
The stack of parts used in this build will total 9.008" (piston 1.433", crank radius 1.875", rod 5.700"), so cut the block deck height to 9.008" for a zero piston deck height. Using a 0.039" head gasket thickness will yield a 0.039" squish. Use only a gasket that is designed for a 400 block, as the gasket MUST have steam holes to match up with the steam holes in the block. Here's an example....
Fel-Pro Q1014 - Fel-Pro Performance Head Gaskets - Overview - SummitRacing.com
Scat #9-400-3750-5700 cast steel Pro Comp crankshaft:
Scat Forged I-beam 5.7" rods:
SCAT Engine Components 25700P - Scat Pro Stock I-Beam Connecting Rods - Overview - SummitRacing.com
Please read Iskenderian's Tech Tip 2005 here....
ISKY Racing Cams - Do It Right. Race with the Legend. Camshafts, Connecting Rods, Valve Springs, Lifters
6" rods will push the piston pin up into the oil ring land, adding complexity that you don't need.
Keith Black #UEM-KB168-030 hypereutectic pistons 22cc dish to make 9.8:1 static compression ratio with 64cc chambers:
Keith Black/KB Pistons KB168-030 - Keith Black KB Performance Pistons - Overview - SummitRacing.com
CompCams #CCA-12-430-8 retro-fit hydraulic roller cam installed 2 degrees retarded:
COMP Cams 12-430-8 - COMP Cams Magnum Retrofit Camshafts - Overview - SummitRacing.com
Howard's retro-fit hydraulic roller lifters:
Howards Cams 91164N - Howards Cams Street Series Retrofit Hydraulic Roller Lifters - Overview - SummitRacing.com
CompCams #CCA-200 thrust button:
COMP Cams 200 - COMP Cams Cam Buttons - Overview - SummitRacing.com
CompCams #CCA-201 wear plate:
COMP Cams 201 - COMP Cams Thrust Bearings and Wear Plates - Overview - SummitRacing.com
Edelbrock #EDL-7101 RPM intake manifold:
Edelbrock 7101 - Edelbrock Performer RPM Intake Manifolds - Overview - SummitRacing.com
Dart Iron Eagle Platinum 215 cast iron heads #DRT-10521123P: (price shown is for one head). Have Dart drill the heads for steam holes before they ship them to you or do it yourself before assembly.
Technical Articles at Greg's Engine & Machine
Dart 10521123P - Dart Iron Eagle Platinum Cylinder Heads - Overview - SummitRacing.com
750 CFM, vacuum secondaries, manual choke carburetor of your choice. I might be tempted here to change the intake to a spread bore like this one....
Edelbrock 7104 - Edelbrock Performer RPM Intake Manifolds - Overview - SummitRacing.com
and run a Cliff Ruggles tuned Quadrajet....
Cliffs High Performance Quadrajets :: Qjet Carburetor Rebuild Kits, Parts, Quadrajet Rebuilding, Quadrajet Parts, Bushing Kits, Carb Tuning
Air filter base and lid to house 14" x 4" paper element. The motor MUST be able to breathe. Snag the correct length stud and a wing nut from your local Ace Hardware. OK to stack two 14" x 2" filters.
Long-tube, tuned headers, 1 3/4" primaries. Use an "X" or "H" pipe before the mufflers.
RPM HP TQ
2000 154 405
2500 195 410
3000 250 438
3500 319 479
4000 386 507
4500 446 521
5000 486 511
5500 511 488
6000 515 451
6500 490 396
Get on the phone with Dart and counsel with them about the initial, centrifugal and vacuum ignition timing for this combo. Oh, and I absolutely agree with Mr. P-Body about the cooling system.