I am no expert, but generally the quality of the OEM parts was just better overall. I am not saying the NAPA ones aren't any good, heck they may be great, but generally after having used aftermarket parts and OEM parts, I can say that in general, when it comes to the major components: starters, alternators, sensors, relays, etc. I tend to lean toward OEM. Here is my reasoning, generally the part store parts that replaced original 15 year old OE parts on my rigs were used up in a few years and if it has a lifetime warranty that is great and all and I got replacements, but for the hassle of replacing a starter every 2 years or an alternator every 3 years, I have eventually gotten OEM parts and haven't had any problems.
The injectors themselves may be made on the same line by the same people, but they generally have a different level of quality that they are measured by also. Random analogy but seems to fit, I went to the grocery last week and they were out of Hormel Pepperoni so the guy says Hormel makes our "house" brand too. Great I grabbed some and headed home. They were ok, but they did not taste nearly as good as the Hormel. Same company made them both, but they were no where near the same quality in my opinion.
Similar is true in most cases with car parts.
If you want to pick up the NAPA injectors, and it sounds like you are leaning that way, then by all means get them, they will most likely do you a good job for many years. IMHO, and it is just that my opinion, no hard facts to back it up, if something lasted for, in your case here 26 years before it presented a problem, and it is a serviceable part, then why not have it cleaned and see if it will last you another 26 years. How many parts store injectors do you think would last 26 years without a problem?
I will also offer you this if it helps, I would be willing to buy the old cruddy ones from you to help you offset some of the cost.
But if it were me I would have the OE ones cleaned and pop them back in. I actually have some that I need to send out for my 4runner, thanks for reminding me.
Either way you will get shiny new injectors to drop in.
Also, need to say, I am a NAPA man so nothing against them. Generally that is where I go for things that I don't get thru the dealer. NAPA just seems to have a better level of expertise than the other chain stores, more like the old stores where I grew up. And generally they know more about what they are selling than even the Dealership parts guys (exclusion here for our MUD vendors and a few other good ones I have run across).
Edit: I had my DD pickup injectors serviced by witchhunter 4 or 5 years ago and they came back looking great. He sent me the test flow data and told me that they were in great shape when he started, to just keep a clean fuel filter in front of them and they should do me for many more years. They can't flow match them unless you have a bunch that you can send and they can pick out the ones that are closest together. And if the injector itself is toast there is nothing you can do but buy a new one, the internals are not serviceable.
i appreciate everyones reply. and if we dont ask questions we will never learn anything. when i had my land cruiser it didnt matter if i bought yota altinators or reman once they got sunk in a mud hole they burnt up in a couple weeks. some faster then others. Once i get it running i got a 5 speed setup i plan on swaping into it. w56 setup got everything nuts bolts. pedals. consol trim. flywheel. slave and master . the whole setup. but need to get it running right first.