"273 rear gears with 700r4, i will find out next week whats its all about"
Well, if you have read and understand the responces in this post... 2.73 gears with a 700R4 will not perform well. The stock 3.90 gears would have done much better. I am hoping for a typo in there somewhere. Perhaps your new rearend is a 3.73 ratio. If no typo was made, I suspect the 2.73:1 rear will come out in the near future as performance will be less than stellar.
Acceleration will be poor and overdrive will be best locked out.
Good luck to you