Come up with a goal - 12.0 sec 1/4 mile or something like that. Either car can get you there but not everyone needs an LS1. They're both great motors/cars.

It takes a fully built LT1 to run low 12s, and thats with a race ready suspension. An LS1 can do that with mild bolt ons and street tires.

IDK why you would want to stay with such a poor performing engine when the LS1 offers so much more and is much easier to work on.

if you really want a ls then get one, but first figure out what your goals are for the car and how much your willing to pay to get them.