Engine decision

[Chevyman680063]

I have one of the GM Goodwrench 350 crate engines in my truck that was in it when I got it back in '03 and it ran fine back then but now the thing leaks oil like crazy. It leaks oil from the back of the intake, from the timing chain cover, from the oil pan, from the valve covers, possibly from the rear seal, and it looks like it's leaking around the exhaust manifolds but that's probably just coming from the oil that's leaking from the valve covers and it's running down the side of the motor. The motor runs ok but it could also run alot better. I'd also like to put a larger cam in it because I love that lopey idle sound and wouldn't mind boosting the HP some. I was thinking about getting another GM Goodwrench 350 crate motor with 250hp 350 ft. lbs. of torque because I wasn't sure how much it would cost to pull the motor and have all the seals on the motor replaced plus to fix anything inside the motor that could be wrong. The motor also puts a little out the left exhaust with just a little bit of smoke but nothing really bad as far as the amount of smoke. I was wondering if you guys thought it would be better and cheaper to just have the motor pulled and replace all the seals, fix anything that's wrong in the motor, and put a larger cam in it, or just to put another crate motor like what's in it and later down the road put a larger cam in it. Thanks.