The Grado Red would only be a needle upgrade, the body is the same. I’d go with a replacement needle.
I have tested the Red at home and was impressed by the pleasant sound but the poor tracking and uneven channels make it a bit overpriced. Other manufacturers also offer more resolution in this price range. If the cart should remain Grado I would recommend to spend a little more money for a Silver with the better coils. A similar warm sound, which however does not have to hide low resolution and offers more clarity, is offered by the Goldring G1006 which would be my personal recommendation (might need to add weigt). Other manufacturers could change the sound signature more, if this is desired.