A starter tune isn't really possible, I mean it can be but it can't at the same time. Mainly because so much has been changed.
The stock VE table and MAF will be all wrong because of the much smaller intake manifold and bigger camshaft.
Did you swap front covers too because the LS2's have the cam signal from the front of the cam and not on a rear cam lobe like the GEN 3 4.8/5.3/5.7/6.0 cam.
It will need a complete redo of the VE and MAF curve to run decent, invest in a wideband as it's a must. If you have a tuner like HP Tuners it's not super hard to learn but it does take time. Otherwise it's likely shop bound for a dyno tune.
