Bud........Marvel/Schebler 241B is the "recommended" carburetor for ALL 8N's. It is really hard to wear out a M/S carb. I'll take yer word for it. Many buy the cheaper Zenith. I do NOT like the Zenith. Ittza yer $$$.
I think you'll find yer money more better spent on a "rebuilt" 4-nipple frontmount dizzy with new points (0.015") set on the kitchen table, stedda a new M/S carby. Ittza yer $$$.
REMEMBER, ittza 2-bolt, 15-min job to remove yer weird 4-nipple frontmount and carry it into the kitchen table to replace the points. (0.015") Just un-snapple yer capple and letter dangle. Replacement is a reversal of the removal ...except... finger start the 2-bolts and then install the rotor. Now rotate the rotor so the OFFSET drive tang fits into the camshaft OFFSET drive slot. Now tighten yer 2-bolts and re-snapple yer capple. Simple, eh?
Many neubie shadetree mechanics don't realize that they can just unsnapple the capple for dizzy removal and then they gitt the firing order scrambled. Firing order is 1,2,4,3 CCW. Most 4-nipple caps are correctly labeled for firing order but neubies swap sparkies 3&4 at the tube.
The OFFSET drive scheme mean you don't haffta re-time yer weird 4-nipple dizzy. Just time it to 1/4" using a 1/4" drill like is shows in the I&T FO-4 manual.
Remember to "polish" the INVISIBLE corrosion from between the points after installation. (0.015") Me? I use a clean $1-bill and clamp it between the points and pull. Iff'n yer really cheap, tear a strip from HEAVY paper grocery sack and use that. .........Dell, yer self-appointed sparkie-meister