When you say LT4 conversion, are you talking about the complete package with heads and all or just the cam kit?

I think this all depends on what you want out of the car? Mouth is correct, If you are looking to build a 11 sec car then the LT4 conversion maynot be enough.

On the 2nd hand, If you are looking for just a little more out of your stock car then it maybe a good choice. The Lt4 cam kit will wake it up a little and mid to high 12's with a few other bolts ons.