99-spec bumper, 94 airbox and IC. Will it work?
 

So i am doing a full 99-spec conversion in a month, but i have a question regarding the airbox and intercooler intakes. They are said to be different on the 99 than on the 94.

https://cimg9.ibsrv.net/gimg/www.rx7...7296526a31.jpg

So my question is, what parts do i need to get this working like on a 99 spec?

IF I understand you. Are you looking to replace your stock 94 Intercooler with a 99 spec one? And intake?

If correct, just go aftermarket.

I want to know what parts are different. I will go aftermarket at some point, but i dont have funds for that yet, and its not needed on a stock engine :)

Also curious about this as well. I remember reading somewhere that the way to mount the front bumper is different for a 99 vs a 94. Is that true?

The only difference is the intake duct, which is an improvement but not a requirement to complete the conversion. You can get the duct online, rdhjapan.
There are about 1000 conversion threads, try searching.

Your best bet is to do the reliability upgrades one by one.