conventional oil to synthetic oil

I have a 1996 caprice classic police package 9c1. It belonged to a retired police officer who used it as a daily driver with no police use (no chases or jumpiing over curbs an island in the street)I recieved the car in March of 2008 and we began to take the car apart to begin some mods that will make it a track monster but still an occassional daily drive. Okay maybe an occassional track monster and a daily driver but anyway the car has 100,107 and we took the motor out to do a top half swap leaving only the short block. We are using GM Performance parts to do an LT4 conversion(Heads,intake, LT4 hot cam, lifters,roller rockers etc...)After taking the motor out last May and letting it sit allowing all fluids to drain from the motor it was lightly and very carefully cleaned and now to start off 2009 myself and my car inthused budies are starting to put the engine back together and we wanted to know if Synthetic oil is an option for this project because I want to use Synthetic oil but one out of the three of us thinks that we can still only use conventional oil because of the milage. Please anyone help because we will be finished putting it together by the end of February and I would like to know which direction I can go in. We are getting ready for track season to test in the month of March and April because that is when the track in New England is opened because of our great winters. Thanks for what ever advise is given.  

with that many miles on the bottom end and not being rebuilt I would use conventional oil.  
Professional hi-performance engine builder

Horsepower sells Engines and torque wins races.

Dont waste money on the synthetic. It wont help a worn out engine. Why all the time and money on the top and none on the bottom? That new top end is likely going to kill the bottom. Your gonna drag race a 100K mile bottom. I would go ahead and put a crank kit on layaway. Running an old engine hard is a bad idea if you have any kind of ring groove because the extra RPM's will let the rings hit and cause major problems.  

The viscosity characteristics of synthetic oil won't work well with that high mileage engine. You'd end up having oil burning issues.

Just stick with a good crude based oil like Castrol, Valvoline, etc.  

Thanks for the info!!!