I just put a Blueprint Motors 383 in my 67 and the intake manifold is leaking. I made the mistake of using the end seal gaskets instead of RTV(forgive my ignorance, it was my first time installing an engine). I've driven the car a handful of times (probably less than 100 miles) with the leak and it's smoking fairly bad out of the breathers on the valve covers. More than just normal blow by. Could the oil leak have damaged a head gasket? I'm planning on re-installing the intake manifold this weekend and I'm wondering if I should replace head gaskets too.