Bell Housing Removal

[68gmcdude]

Hi... I am new to the site. I have a 1968 GMC stepside with a 250 cid motor and 3-speed manual transmission. I want to replace the clutch. I was able to get the transmission out but was surprised to find that the bell housing also has the rear mounts/supports for the motor. I removed the support bolts and jacked up/supported the motor just enough that I could pull the bell housing off. The problem is that there is not enough room to pull the bell housing out due to the bottom of the cab and the cross member. The cross member can't be removed as it is riveted in place. How can I get the bell housing out so I can get to the clutch? Thanks!