Thx for constructive reply WormGod

C4 Vette is a bird cage frame RWD, it wouldnt work to top it with VX body........
SBC has been dropped into Austin Mini, Range Rower, Trooper II and Fiero to mention few, mostly it worked fine.
You are right WormGod to bring LT1 to 450HP would be the least of the problem. What makes this a bit easier is that VX does not have a single computer for engine, tranny, TOD etc. That allows GM ECM (the computer) to be a stand alone unit. The VX ladder frame with addition of few gussets should be stiff enough to handle the torque.
Transaxles well I dont know, to have them locked and flooring it on uneven surface, an axle or two might give up.

Word of wisdom: VXLT1 shall see many BMW X5 4.4i in it's rear view mirror