225 Hemi head

Yes, back in the day they were known as Semi-Hemi in a nickname, "Hemi" didn't come out till '64 for Nascar.

BUT, this was a time when the combustion chamber wasn't completely Hemispherical, OR Polyspherical either. That's where the garage nick name "Semi-Hemi, came from....But this same "area" was sort of, twisted I guess.....I don't know of, or ever heard of a Slant 6 being called a Semi-Hemi, as those \6 were all in Aussie! Even tho, the 225 can provide high HP if sat up right for the task at hand.....

But, in all reality, weren't these motors, the 170 and the 225, "wedge" types?

On your 241, bored .030 over, would make it a 246.....See:

Cylinder bore size: 3.4375"
Cylinder stroke size: 3.25"
# of cylinders 8
Over bore .030, makes it: 245.525253902654, or 4.1L
This does NOT include combustion chamber cubic inch.