Piston pin issue?

I have KB pistons with full floating pins and Eagle H beam bushed rods. I was trying to get rods, pistons and pins together but they seem to be very "sensitive". I can put the pins in the rods with no issues, I can put the pins in the pistons with no issues. I just can't seem to the complete combo together. Almost like the top of rods are hitting the bottom of the pistons and not allowing me to slide them together straight.
Anyone experienced this? Is this just such a critical measurement that that I am just not getting everything straight enough?

I had a set of kb 162 pistons for a 383 and a set of Eagle rods. The small end of the rods were too wide and wouldn't fit into the piston without narrowing.

I have the KB841 (I think off the top of my head). The rods fit between the piston skirts fine. It just seems like they are not lining up with the rod end

Put some grease on the top of the rod and try that, if the grease transfers to the piston its time to take action

Everyone else's went together with ease?