Well then, it appears you have your answer.
Why did you ask, if the answer you accepted, (and evidently called Textron and McFarlane) got their answer?
My first two questions still stand.
Have you seen this pump? Touched this pump?
Aircraft spruce page, weldon pumps.. listed at the top is PMA"d pumps,
17 boxes down is :
Cessna Single-Engine & 337 Aircraft 18000-B C291504-0201 Fuel Boost
08-07083
So, PMA'd, and listed for 337 aircraft.... Part number is correct, and if you call Weldon, I am pretty sure they will tell you it is the correct number.
OR
Don't take my word for it... Ask Weldon.
640 Golden Oak Parkway
Cleveland, Ohio 44146, USA
Info@WeldonPumps.com
PH: 440-232-2282
FX: 440-232-0606
Regards,
Randy