I don't know where else to post this but I installed a new Denso fuel pump in my 1999 Grand Prix GT. I had a ***** of a time trying to get the new pump to seat so I could install the snap ring. I had seen a few videos on you tube which made it look so easy and a drop in fit.
I spent 3 hours trying to get this pump to seat with no luck. I went back to the computer and saw a post on Google by some one suggesting using Vaseline around the o ring to seat the pump easily. I went back outside and sprayed some silicone around the o ring and the pump dropped in very easily and I was able to install the snap ring with no problem.
I am mentioning this because breathing in gas fumes for 1/2 a day is no fun and I cant tell you how pissed I was that no one mentioned this in any of the instructions or videos. To be fair all the videos are showing a screw type twist and fit lock for the fuel pump not the snap ring which was on my GT. I don't know what system is currently in use but hopefully this tip will save you from a miserable day.