On a 2004 silverado LS with a rebuilt regular 2000 5.3L engine i needed to replace the transmission ( with a 1999 4L60E) torque converter and flywheel. however, after multiple trips back and forth to ensure i have the right parts i cannot get enough clearance to spin the converter and flywheel when bolting it up.

 

Three things ;

#1 , maybe you don't have the torque converter seated all the way .

#2 , maybe the nub on the converter or the recess in the crankshaft are dirty/marred and not allowing proper fitment .

And , #3 ; This is a forum exclusively for 1982 through 1992 Chevy Camaro /Pontiac Firebird cars only . If my answers #s 1 & 2 above don't help , it may be best to try to find either a Chevy truck forum or a transmission forum to get people familiar with your truck/transmission in specific .