CV Boot installation problem.

Bought universal boot kit from Autozone. Instructions say to cutoff old boot
retaining the thick molded ring which mates to the tulip CV joint. Now for the
issue; the new boot is not big enough to easily fit over the molded tulip ring. I
have a spare boot as the first boot is on the shaft and filled with grease. Since I
am unable to stretch the end of the boot to fit over tulip with ring. I was able to
fit the tulip ring into the spare boot. My question is with this so much tension on
the boot will it last any reasonable length of time? Or should I try to get OEM
boot from Toyota dealership?
Well, no reply :^( Decided to use the boot and if it doesn't last, I will replace the halfshaft. New question, how much grease should be in the boot? I scraped as much grease as possible from the boot that did not fit and put into new boot. Since this is not exactly easy due to bellows shape of boot, there was not a lot of grease to put in new boot. I did put a good amount of grease into tulip housing. Should I be concerned with amount of grease inside the boot itself?