A few months ago I discovered that my cv boot was torn on the front right of my runner, so I replaced the entire CV axle on both sides with NAPA axles. After a month or two I got back under the runner to replace the tirods, and noticed that the inner boot is rubbing on itself and has already torn AGAIN on BOTH sides.

Apparently the NAPA's inner boots don't extend as far down the axle as the stock axle. NAPA has agreed to give me replacement axles at no cost (if I return the old ones), but now I'm left with two options. One is to put the new NAPA on and stretch the boot, and the other is to fight with them over a full refund and buy my axles elsewhere. I originally thought I'd just stretch the boot, but I can't figure out a good way to KEEP the boot stretched, as the shaft diameter lessens as you go towards the outside. Anyone have any ideas?? I could really use some help as I would hate to have to replace these axles for a third time

Those NAPA boots are hit and miss. I've gone through 3 and the boot on the passenger CV seems to be holding up great on this one. IMO, go find some cv boots for a porche. They have a lot more room to stretch.

haven't checked in to it, but you can just buy an oem boot kit and swap the boots if the savings is still there, also check this out,i think also someone has used porche boots as well
Porsche 930 boots

i've been wanting to do this and see if it pays off...
Boot Slide mod. No more blowing cv boots. - Tacoma World Forums

also another possibly option, but there are much debated pro's and cons going this way, read up on them, if i had the money i would run them as i'm not hard core enough to really worry about breaking teh front diff...
Lotus Axles Chromoly -

2 options

Gerdo stretched his boots by simply using a couple hose clamps. Even though the axle narrows down he reports no problems with it sliding back or leaking. He has a thread about this. Stretch your CV boots

Also, there is a thread on ttora showing you how to use a piece of the old boot under the new boot. Here is a link on tacomaworld about the thread on ttora

Ha, I see izzardking already referenced the ttora one