Just to add to this topic...
Assuming the cc/minute spec on the a 4-hole injector is close to the same as single port injector for the same engine AF requirement, can we assume the 4 hole style injector has smaller ports? Since an early 22RE would not be considered a super clean fuel burning engine, I would imagine switching to a 4-hole fuel injector on a 22RE would be more prone to injector clogging..... lots of fun to diagnose.
The Japanese engineers designed and spec the position of the injector and how it atomizes the single fuel stream inside the cylinder for a good reason. Switching to a different injector with a different spray pattern may be better or may be worse than the stock injector.
Just for the record, as part of my initial research for my engine rebuild, several months ago I discussed 22RE injectors with two very knowledge Toyota experts, each had a different opinion.
That's just my worthless opinion.
Gnarls.
