Yes, he can stay under his $4500 goal, with an LS motor or he can go over his budget, with some other motor...b18c (itr), b18c (gsr), K20a, etc.
The only low mileage (about 40,000 miles non oil burning) motors will come form Japan junk yards.
He won't find a USDM gsr with 40,000 miles, for...