the lq9 will swap right in place of the lm7. all accessories, fuel rail, etc., all interchangeable.
as far as i know all lq9's are 24x like your '06 lm7.
the hardest part is, trying to find a low mileage gen3 engine.
consider swapping over a gen4 engine. it's not difficult and only requires a few more steps. ling 58x to 24x crank/cam converter, tap block for side mount knock sensors and a 4bolt to 3bolt throttle body adaptor.