Pickup/Early 4Runner Tech
3.4 here is why
the 2.7 and 3.4 are both great engines! I wish I had a 2.7 in my 86 4runner. It has a 22re in it now.
You already have a 3.0 the motor mounts should match up to the 3.4 and your R series tranny will bolt up to it also. This will save you from buying adapters or a tranny too...