The ZZ3 is a good motor. It can easily be stroked. With a camshaft/valvetrain change, you can easily get 400+ HP from it. I'd be a little nervous about turbocharging with the hypereutectic pistons, though.

High Output 350 (ZZ3)
PN: 10185072
Displacement: 350 cubic inches (5.7L)
Horsepower: 345 at 5200 rpm
Torque: 387 lb-ft at 3250 rpm
Max RPM: 5800
Compression ratio: 9.8:1
Bore & Stroke: 4.00" x 3.48"
4-Bolt Mains
Forged steel crank
Pistons: Cast hypereutectic aluminum
Rods: 1053 forged steel "pink"
Heads: Cast aluminum, angled plugs, 58cc
Head specs: 1.94"/1.50"
Camshaft: Hydraulic roller tappet
Cam specs: 208/221 .474"/.510" 308/316 (advertised)
Idle: 750 rpm