The 3.4 is one of the easiest swaps you can do fer a yota. The 3.4 bolts up to your engine mounts and will bolt up to your manual when you get one. The only other thing big your going to deal with it getting it in the truck and swaping out the auto ECU for the manual ECU.... plus some wire's and what-not....
With the Chevy 4.3 Vortec, these are getting pretty common and there are a lot of write-up's on the swap it's self. I couldn't tell you how easy or hard the swap will be, but i am almost sure that the 4.3 bolts to our yota manual tranny's...
Don't be afraid of the 3.slow's... yes, there is a lot of hate for them in the 4 wheelin world, but mine has 210K on her, and she is absolutly flawless.... i love my 3.slow, the only thing i don't like is the fact it's not a HP or Torque monster....
Good luck with your new find, and keep us informed with loads of pics and start your self a build up thread....
military_stang
