Short answer--No. The engines are different; the base model is a 4.6L Northstar engine. The V is 4.4L Northstar. The base models also use a 5-speed transmission and the V's are 6-speed. There also other upgrades that would also need to be done. Brakes, wheels are all different.
Definitely recommend a car upgrade rather than a re-model. Given the will you can find a V at a non-V price. I just picked up my 2006 <?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-com
CPO</st1:stockticker> V for $42K a solid $10K less than the going rate in my area… the deals are out there if you look hard enough... Good Luck... One thing to note is why you would want the upgrade... performance is not noticable unless you're a real car guy and only an XLR owner would know if it's a real V... buy the badging and don't tell anyone... LOL