LS400 Timing belt job/won’t start

I tried to do my first timing belt job (and water pump and Ted my fan bracket bearing froze up and the serpentine belt was sliding over the pulley since the timing belt was 100k miles and 10 years old. I did a step by step tear down of the engine and got to the belt. Set at TDC and pulled spark plug 1 out to stick a rod in to confirm it was at the top of the stroke. Set belt on timing marks of both cams and reassembled vehicle. Doesn’t crank up now. Sounds like it wants to but just doesn’t get there. What could I be missing? I thoroughly check all the connected plugs that had to be undone to complete the job and am just lost now. It’s a 1994 LS400 with 4.0 V8 (1UZ-FE first gen)