More updates: I bought Lokar engine and transmission dipsticks. I'm a little concerned about the length of the engine dipstick. You can see in the pictures that the Lokar engine dipstick is quite a bit shorter then the stock 5.3L dipstick. I'm using the Pacific Fab/Tilden oil pan, which is different then the stock pan. According to folks at Pacific Fab/Tilden Motorsports this is the proper dipstick to use with their oil pan (and 6-quarts of oil). I'll have to confirm the length once I fill the engine with oil.
Lokar XTD-34L60EFM transmission dipstick for 4L60E
Lokar XED-5008 LS series engine dipstick
Comparing length of stock dipstick versus the Lokar