i have an '87 W150, it was my first truck and I just put a '78 360 in it.The motor has a mild cam and a high rise aluminum edelbrock intake with a 600cfm edelbrock offroad carb.When I rebuilt the motor (it was my first rebuild) I think i messed something with the head because it leaks oil out of the exhaust manifolds. I'm guessing I didn't seat the valves properly but I'm not sure. If that's the case how much would it be to have done or would it be more worth it to pull the motor again and do it myself? Any help would be appreciated. I'd like to get the work done so I can register it when I get back from my station in Korea next spring.

 

Where new valve stem seals installed? Pull the manifold/s off and see where it's coming from.