Hello and welcome to OSS.
Please take some time to introduce yourself in General Chat, and post some pics of your 750L.
One fix is to do what I did, install an 1100 engine, so you don't need 10000 + rpm anymore.
I have mounted 2922's on BST36, 38 and 40mm carbs without any issues. The ones on my B12 engine (36 carbs) were previously on the GSX-R750 (38 carbs), they still fit nicely.
RU 2922 is the correct one for slingshot carbs. I've fitted many sets in the past, no problems.
Maybe the ones your mate offered you were not new anymore and have been "pre-stretched" a bit?
Hello and welcome on OSS.
@RickLeeplease post an introduction about you and your ride. Now you have a good example.
@eskimo619remove the ignition lock and take it to a locksmith. He/she will make a key which will fit the tank and seat locks too if they're still original.
Hello and welcome to OSS.
Please take some time to introduce yourself in the general discussions section, and post some pics of your bike. We like pics.