Installing new motor mounts?

I just had some Longtube headers put on and need to replace my motor mounts...I know I should have replaced em when the headers were done, but will I be able to put them in without loosing the headers or is it too tight of a space that I will need to remove them? thanks

 

What type of K member do you have?

 

I replaced mine with my headers on but mine was out of the car hanging in the air on the hoist. So yes if its out of the car and idk if it's in the car.

 

I still have the stock K member