Slant six dies in gear

How does the car respond to throttle in all other driving scenarios? Does it make good power? Does it cruise smooth? Does it take full throttle without coughing or backfiring? Figuring out if you have a cam timing, ignition timing, or just a carb tuning problem over the internet can be tough.
Highway and town cruising are excellent, tons of power, cruises smooth. Drives like a dream. Just the initial get go from P to D and getting going at lights. Little bit of initial hesitation when you first hit the throttle from a dead stop which is why I initially thought it was a crab problem.