Thank you for supporting Pro-Line products. We Currently offer a few products for the Slash 4x4, The rear arms off of the 2wd Pro Trac Kit will fit the 4x4 (6062-02). Our Power Stroke Shocks will fit the 4x4 (Front 6063-00, Rear 6063-01) and we just came out with 17mm wheel adaptors so you can run 1:8 wheels on your Slash 4x4 (6064-01). Just heard from the R&D team that we will be releasing an under tray for the 4x4 on the 15th of this month.
We currently release new products on the 1st and 15th of the month. Please let me know if you would like to be added to our e-mail listing and be automatically updated with new product information as items are released.
Please let me know if you have other questions and I will be more than happy to help in any way.
Thank you and have a great day!
Pro-Line Customer Service