This is what I went with and have a 4.0 Whipple on it.

GM 6.0L Cast-Iron Engine Block
Eagle LS1 4.00-Inch Stroke Crankshaft, 24X Tooth Reluctor, With
ESP Armor Finish

Eagle LS1 6.125 H-Beam Connecting Rod Set with Upgraded ARP
2000 Rod Bolts, 2.100 Crank Journal, .927 Wrist Pin

Diamond Racing Forged Piston Set: 4.010 Bore, 4.000 Stroke,
6.125 Rod Length, 1.115 CD, -28cc Dish, Includes HD H-13 Wrist
Pins

Texas Speed & Performance Exclusive Total Seal Ring Set: 4.010"
+ .005", 1.5mm AP Stainless Top, 1.5mm Napier 2nd, 3mm Oil

ACL LS1 Rod Bearing Set

ACL LS1 Main Bearing Set

Camshaft Bearing Set for LS2 and 2nd Gen LS1 Engine Block 1 33.99 33.99

Full Block Work and Preparation: Vat Block, Line Bore, Install
New Cam Bearings, Bore/Hone with Torque Plate, Balance
Rotating Assy., Line Hone

ARP Main Stud Kit for LS1/LS6-Based Engines

GM LS1 Oil Restrictor

GM LS1 Oil Galley Core Plug

GM LS1 Large Coolant Plug

GM Engine Block Small Coolant Plug, LSx-Based Engines