Distributor removal question

[89muscletruck]

I am removing my intake mainfold on my 94 GMC so I can replace the seals. My Haynes manual tells me that before I remove the distributor, I need to position the engine to Top Dead Centre for the #1 cylinder. My question is, is it nessecary to do this when nothing inside the engine is going to be messed with?
A buddy helped me do this on my 91 four years back but I cannot rememeber if we bothered to place the engine at TDC. I've never messed with a distributor by myself before, and I'm despriately afraid to screw up my engine.