What does a budget heads/cam 346 build sheet look like?

Speedway's 400+ hp LS1 recipe keeps the stock block, rotating assembly and heads, and gets its power from breathing and fuel:

• Cam kit with matched valve springs, retainers and pushrods, so it can rev without valve float.
• Intake and throttle body: a higher-flow intake and a suitably sized throttle body. Swapping heads can also mean changing the intake, since the port shape must match.
• Exhaust: headers (long tubes if they fit) and a cat-back.
• Injectors sized for the extra airflow.
• A custom tune for air/fuel and timing.
• Cooling: a good radiator and electric fans for the added heat.

Room to grow: Speedway notes porting the stock heads and moving to forged pistons. Its 500+ hp recipes add forged pistons, H-beam rods and aftermarket heads.

LS1 bottom end	What Speedway says it handles
Stock block and rotating assembly (anything bolted on)	400–450 hp and about 400–450 lb-ft, reliably
Forged crank, rods and pistons	600–700 hp and similar torque — suits a blower, turbo or big nitrous with proper tuning
Max displacement on a stock block	383 ci: 4.000 in stroke crank with 6.125 in rods