Our engine bays are a bit shorter than those of 1G/2G so it's tough to fit anything bigger than a 4G. I saw a thread on Tuners a while back where a guy swapped in the v6 from a 3000gt and it was EXTREMELY tight against the firewall with the twin turbos. Moving to a single front mounted turbo might help. It CAN be done in the sense that a skilled fabricator can do just about anything, but it's not really feasible in most cases. But, one of the biggest cons to the idea is that there isn't a lightweight v6 out there to compete with the durability and power potential of a 4g. Particularly given the relative ease of a 2.4L stroker. It's not like toyota where the v6 from a Tacoma is just as tough and weighs the same as the 3sgte. Even if you make it work you're getting marginal performance at the cost of a less reliable and significantly heavier engine.