Re: pups for 355
Early Gibson pickups all varied greatly in their construction (windings, wire types, magnets etc), so it is difficult to categorize them all the same way. These days, obviously their production is a lot more homogenized but they offer many various types of humbuckers, so again it is difficult to say "i do/don't like Gibson pickups" because there are so many different ones.
Something you might want to consider tho, is not just replacing the neck, but getting a well matched set of pickups. Often pairs of pickups are constructed in such a way that they will complement each other output and and eq. This way, both pickups should sound good with whatever amp settings you are using. On this forum, people have tried pretty much every combination you can imagine so if you want to know about certain pairs working together, the information is here somewhere.
Just dropping a pickup in and keeping the other original, you run the risk of the new pickup being a mismatch. Believe it or not, i have had the experience of a jazz neck completely blowing away a Gibson bridge (in this case a 57 model) in not just clarity but also output to the point where the bridge pickup was unusable due to its lack of output, bass and treble detail.
If you are concerned that the jazz does not have enough push for your amps, don't be. Its got plenty. Neck pickups sit in a position where there is increased string amplitude, so they are naturally louder/bassier and therefore are much better with a lower output. There is good reason why the JB (a screaming hot output bridge pickup) is so often paired with a jazz or a '59. Btw...dont get a JB for your 335. Semis work best with more vintage output.
So...a jazz is generally considered a clear, defined and articulate neck pickup - but that is compared to other comparable pickups (such as the 59, PG, seths etc). You may just find that it is all of the aforementioned, but also not a good match for the pickup you are keeping. This is why i reckon you should consider doing a complete electronic overhaul.
Keep the original pickups and wiring harness as a complete and unbroken set just in case for whatever reason you decide to revert to completely stock one day.
Get a complete new set of high quality 500k pots (i like Bourns the best because they last forever and feel so slick) as well as a new switch, jack and caps.
Then the world is your oyster - choose a pickup set that most closely sounds like what you are looking for and the pair will work together giving you more sounds and more sweet tones at your disposal with no need to change your amp settings for each pickup.
As a pair - you can do a lot worse that the tried and true '59 set. These are great pickups as they are, but also will accommodate pretty much any magnet you care to put in there. This is a good thing because changing magnets is a pretty straightforward and simple process that does not involve the nightmare of pulling out the wiring harness. If you find that stock 59's don't sound killer, then you can fine tune the sounds with magnet swaps until you are completely happy with every aspect of your guitar's tone.
If the idea of a pair of 59's doesn't suit your because some people use the word "boomy" to describe the 59N, then a jazz Neck and 59 bridge might be just the ticket.
