it would fit in physically. but it just wouldnt be worth it. u would have to fabricate mounts. and then all the computer/electronics... woah that would be major, major hours. it would be just as easy to go buy a truck with an 8.1 and set a van on that frame lol. im not gonna say this is impossible... just well insane. it would be way easier to go and get a 454 7.4 v8 carbed and use that.

if u did want to put an 8.1 in u would pretty much need to go buy a truck with one and completely strip it. the vortec 8.1's are nothing alike the 5.7 350s 04 454's or even the vortec 5.7 and 7.4. they are a complete different design.