I've helped someone do it from the bottom for a bit, he did most of it. It all depends on what you have available, workspace, etc. You have to be able to lift the front end of car up fairly high.
How many miles on that LS1?
2106 Subaru WRX
2001 Trans Am WS6 A4 Sold
1970 Camaro Z28 A2 Clone Project (0rwhp) -Primer