Cracked Exhaust Manifold - GM Inline 6

[pckeen]

I'm looking at a boat which will involve a restoration project. It's a '74 Chief, and I'm told the engine is a GM Inline 6 160 hp. The seller advises the motor runs well, but there is a cracked exhaust manifold. I've dealt with a few outboards, but have never worked on an I/O. I gather that a new manifold will run me $500 - but how tough a job is it to replace this. With a cracked manifold, are there any other engine issues that typically go along with this?

 

[VE8EV]

Manifolds get cracked by freezing so there might be other issues lurking inside the block. Also, when manifolds freeze they can crack on the inside and leak water into an open exhaust valve. If the engine doesn't leak or "make oil" (water leaking into the crankcase) and still runs ok then it's not at all difficult to replace the manifold. Lots of bolts on a six as it's integrated with the intake manifold.

 

[Bondo]

With a cracked manifold, are there any other engine issues that typically go along with this?

Ayuh,.... As noted, I'd be lookin' for a matchin' cracked block,......

 

[pckeen]

Thanks - I was figuring that the cracked manifold might have been from improper (or no) winterization. I'll figure on having to replace the engine....