I just measured mine.February 13 2018 at 2:06 PM
|kleandan (Login kleandan)|
Response to Long cast ex manifold ?
I have the C5 casing number versions and your question caused me to go and measure mine with a caliper.
They are a nominal 2.5" inside diameter.
I know the flange is an odd size with the bolts and edges being pretty close to the 2.5" diameter hole.
This means you will probably have to make a flange that will fit because most of the stuff that might fit will be made from cheap ass steel and not hold up without warping.