although alot of ppl will say just go buy a ls1 powered VY it can be done if you shop hard and take your time buying the items required to carry out the conversion
Eg it would make sence to buy a complete damaged gen 3 vehicle .At pickles last week a white VT SS series 2 hit at the front sold for $2200 dollars.(now this is a rarelity not the norm) but this would be a better way to carry out your conversion
then selling off what you dont need. but to work out wat its going to cost you take a figure that you think its going to cost you and then double it..