Pull engine and trans together?

I had to remove my timing cover (with engine in car) recently for a separate issue. I got it back together and now have a pretty bad oil leak between the timing cover and oil pan.

2nd issue. My transmission is bad. I have purchased a built street strip 904 to replace my blown 904.

The question: would you all just go ahead and pull the engine and trans together so I can address my oil leak with the engine out of the car, swap transmissions then put them back in together?

Or, would you leave the engine in the car and do the jobs separately. I've never pulled the engine/trans together so just looking for some thought and feedback. Thanks in advance.