i deleted the catylic converter from my 89 260E in hopes of more performance, and was wondering if theres any effect it will have later on down the road? and one more question: what would be the total cost of a grill update for the same vehicle including parts + labor

 

Unlikely you will get more performance unless the engine is "retuned" and even then it will be minimal.
Need to consider whether the vehicle (less cat) will still meet legislative in service emmission tests. Depends on where you live.
Stuart