I run the reds 721 superveloce
and the 723 truggy engine 2143 x one pipes
the new gen 3 carb is far better than past reds carbs.
easy to tune and hold a tune.
Very fast engines the 721 is great in truggy as well.
nothing wrong with with an os ad3 2104 or any outher current speed
also the protek ro3 - rm samurai are great as well
alpha run good while they run ive owned 2 and broke rods in both.