has anyone tried the tdc method for changing seals as opposed to airing the cyls up? it works quite well in the lt1 engines i was wondering if it will work on the 4.3 also thanks

The last time I changed valve spring without air, I used soft rope in the cylinder, slowly by hand bring the cylinder up til it stops. The rope crushes against the valves and keeps the from dropping at all. To remove the rope, just back the cylinder down.