I just did my square shaft and i looked into not using the cv.... found that if i used the stock crossmember with-out the cv it was coming very close to hitting my shaft, at full drop im not sure it would clear, the cv is alot longer so i used it, thing is the cv's arnt really needed on a non balanced driveline anyway and if your using smaller diameter material like a round tube you should be able to get away with not running one...... when i do my flat crossmember im going to go with a single u joint just because its simpler and can hold a higher angle