Helpful answerI had an Asus ROG Strix RX Vega 64 OC (298 x 139 x 52 mm) installed in my set-up - a milimetre job!
To be able to insert the GK, I had to remove the part with the power plug and then re-install it. Also possible with 2 left hands.
I used it with my MacBook Pro 2017" (Touchbar) and had more or less no problems - just software-dependent.
The dimensions vary depending on the manufacturer (ASUS, MSI etc.). The dimensions mentioned should help you as a guide.