just overall in general i try to stay away from SMP/Standard Motor Products, and Crown for critical items. Their 30 day warranty says about all. Bosch fuel injectors carry limited lifetime warranties
bosch, borg warner/(BWD), and (seimens)/ford motorsports all make very well built fuel injectors and generally have at a minimum 24mo warranties, if not LL warranties
as a secondary note, it's worth it, if possible to just have the OEM injector cleaned and rebuilt, now give the 3.7s injectors aren't retailed at 120+ bucks per injector, so a 60 dollar oem or bosch injector brand new or remanned may make you sleep better at night, and thats all that matters, is it works dependably, and you trust it.
Me personally, i dont have a problem replacing an injector or 6, as long as i trust the result is going to be semi-permanent , that is i expect them to thump gas for me for 250kmi , i also dont have a problem with rebuilding them either, they're surprisingly simple devices , ignoring bad manufacturing the worst thing you can end up with is injectors with GARBAGE o-rings RE: Crown and their occasional use of recycled garbage bags or whatever they use to make the orings and such. #censored 2 paragraph rant# you know what, i think you get it heh, i've had to vacuum crown o-rings out as i removed injectors from a month old install, i think i was as ticked off with it as the owner was. Don't get me twisted tho, not ALL of crowns stuff is garbage, they just dont have the quality track record on rubber components as the big 3 mentioned above.