Porting stock style cast 5.0 exhaust manifolds

[87xjmike]

I'm in the middle of instsalling some ruff stuff shock towers along with some bigger shocks so i figued it'd be a good time to swap to the cast manifolds in my 97 mountaineer.

Has anybody tried porting these? If so any problems with cracking? I'm sure they'll flow better and yeild a little power, I'm a little concerned about increasing the potential for cracking as we all know is already an issue with our crappy mani designs.

Thanks,
Mike

 

[Rick]

There have been a few threads about cracked exhaust manifolds. I'm not sure you would see enough performance difference with w a stock manifold to make the process worthwhile.

 

[87xjmike]

There have been a few threads about cracked exhaust manifolds. I'm not sure you would see enough performance difference with w a stock manifold to make the process worthwhile.

Yeah I know all about the tubular ones cracking. I’ve dealt with them as I’ve had three 5.0 expos. The cast ones seem to hold up much better and typically don’t need milling of the surface. I’m going to port as much of the blockage out of the gasket as I can. I’ll post results here.
I know for a fact if you can open up ANY exauhst manifold at all to closer gasket match it will yield power. It’s clearly limited with these due to the bolt access protrusions into the flow. But the smoother I can make the transition the better.

Just curious if anyone has done it to these cast units with no cracking