Header install/steering whacky HELP!

ABUNAI NISMO

I had a friend install headers on my Z. Note: the engine was lifted. Bad news
Afterward, the steering wheel was 10 degrees right and was loose enough to bring almost back to center without much tire direction change. During brisk acceleration and moderate to heavy turn in/out the wheel also vibrates moderately..OH no!
I brought back to friend explained issue. Spent sometime on lift adjusting wheel/adjusting under the car near the steering shaft, etc. the way he corrected it which I’m learning now was not the right way was adjusting the steering wheel inside the cabin... what!?!?

My conclusion (hope this is the worst of it)
The male/female spines were not lined correctly and need to be fixed. With that in mind so does any adjustments made in the cabin to correct to steering to center.. oh my gosh!
Secondly, when the engine was set back down it was set to close to the steering assembly - hence the vibrations in the wheel under acceleration and right turns.

This is embarrassing for me to post. I lack knowledge and the experience. I will learn and be better!

I appreciate any and all input. Thank you! Stay safe/healthy!