The real key to an LSX motor is the power. How much does it cost to build a sbc to 400+ hp at the crank with fuel injection and have it live 150K miles???
An lsx can be had turn key for $3-4K. That includes 400-500 hp, aluminum block, fuel injection, and a far more solid foundation for a future performance buildup.
I have built 5 SBC's for my car over the last 12 years, I went LSX due to a lower cost and increased performance. Heck I am using the complete stock LS1 fuel injection and making a reliable 1000 hp with just good rods, pistons, and turbos. You just cannot do that with a mostly factory SBC or even BBC for that matter.
