I’ve got a 383 stroker with an aluminum manifold and it keeps leaking oil out the back of the manifold my mechanic took the manifold off and did everything correct as far as sealing the gaskets and cleaning everything up and he used a sealant instead of the gaskets on the front and the back they have tried different sealants instead of the rubber gaskets and it still leaks oil out the back I’m sure this is been addressed before here but I am at my wits end. Maybe it needs more torque than a normal 350 engine? He did check the gap between the manifold and the block and he said it was the same all the way across and also I don’t know if it matters but it only leaks out the back on the passenger side and this is a new engine it might have 4000 miles on it

 

While it is probably unlikely, could check for cracks in the manifold or the block. Is the leak just a seeping type leak or is it more like letting liquid flow?

 

It is a Seaping Oil leak

 

I would check for a small crack and either the manifold or the block surface.