I have a first half 87 N/A. The fuel injectors were different from 1st half to 2nd half of 87. Does anyone know what the correct part number for 1st half fuel injectors is....or where I can find it?

 

in the FAQ at the top of this page.

 

They have the same part number: 195500-1350

From the FAQ...
What size injectors does my RX-7 use? What colour are they?
Year Engine Plug Size Colour Part #
84-85 13B NA, low square center, 680cc, orange, 195500-0900
86-87 13B NA, low square center, 460cc, red, 195500-1350
86-87 13B Turbo, low square center, 550cc, tan, 195500-1370
88 13B NA, high square offset, 460cc, purple, 195500-1350
88 13B Turbo, high square offset, 550cc, purple, 195500-1370
89-91 13B NA, high oval center, 460cc, red, 195500-2010
89-91 13B Turbo, high oval center, 550cc, purple, 195500-2020

However, I have 2 sets of high impedence S4 460s that have RED tops & offset tabs, not purple like the FAQ says.

I also have a set of low impedence S4 550s with PURPLE tops and centered tabs, so again this differs from the FAQ. So don't go by color, go by offset and resistance (if you can get an accurate measurement).