I'll have to take pics and post them showing the differences.
Yes, you better do that.
On the 440Source casting I had (about 5 years ago) I hogged it out enough to easily get my thumb in and never came close to breaking through the walls. The toughest part to grind is the slotted opening to the impeller and that's virtually impossible but the rest was no problem with a selection of cutters.
Here are some pics showing the size difference.
The difference isn't on the front side, it's on the back where it faces the engine block.
Side by side of older 440 Source and a factory cart iron.
Measuring the cast iron one.
Measuring the older 440 Source before adjusting the caliper.
Measuring after adjusting the caliper.
I don't see any way to grind that one out to have the same size passage as a factory one.
I still need to take pics of the new 440 Source version.
