The LQ4/9 Iron block is a GEN III Motor. This still uses the cam sensor in the rear of the motor and the knock sensors in the valley just like your 5.7 in the car now. The LS2 is a GEN IV and requires a LS2 Timing Cover, Timing Set, Relocated cam sensor and knock sensors. This may seem overwhelming but is easy. Your choice should really depend on your goals. If you are looking for a good street car with alot of power and some extra weight will not be a factor for you I would go with the iron block to save some money.
If you plan to race the car and anywhere you can save weight is important, use the LS2 block.
If you would like we can also rebuild your factory block. Of course this all depends on what your plans are for the car.
Shoot me a PM or email @
Leom@4wre.com and I can get some pricing together for ya.
Thanks,
Leo