Dropping a junkyard 5.3 is cheaper than building a 383, but as soon as you open up that LS to refresh it, the cost advantage goes to the SBC. It depends on what you're comfortable with.But there is something to be said about how awesome a 383 can be, and the fact it's a "period correct" engine build, but the cost associated with it is multiple times more than an "average" LS swap.