Ok, I have a 94 4runner with a 3.0 V6 and a recently rebutilt A340H automatic transmission.  The 3.0 just recently locked up and is in need of replacement.  I want to keep using the tranny since i just got it back a month ago.  I was wanting to put a 5vz-fe 3.4 V6 in the 4runner or a chevy 4.3 V6.  which would be the easiest and best way to go.  i am just an everyday driver that uses the yota for hunting and fishing and sometimes trail rides.   please help  

Must have had a hard life because Toyota engines just do not lock up unless abused and run out of oil. On the swap, I would do the 3.4 at most because the greatly increased torque of the 4.3 can shorten life of the newly rebuilt tranny a good bit. If it has big rubber on it and power is the reason that you want a bigger reason, you would be better off to regear axle deeper and stay with stock motor. This would improve performance and extend tranny life too.