PW- I actually had the car running fairly well with a diff in front on outdoor asphalt this weekend. I broke an outdrive on my spool (it was pretty old) had to thrash so I put the front diff in and just ran it really tight. It ran quite well. Gave good on power steering with a little better mid corner than I had with the spool. Overall the car ended up pushing a little in the main but I think that was a little more of a tire issue than a diff issue.