I just changed my valves springs and cammed my car and I'll tell you this right now. BUY NEW LIFTERS. My motor now sounds like a diesel cause the increased valvetrain noise. My car already had long tubes so I'm not sure about the difficulty of that but it's pretty easy to do the rest in the car. Just use a compressor to keep the valves from dropping in and it's simple. Well I shouldn't say simple just not hard just tedious with the valve locks. If you don't remove the heads PLUG YOUR OIL RETURNS. I dropped 2 locks down them somehow and had to fish them out with a magnet.