what are the stock size fuel injectors on a '90 5.7 iroc? I thought that I read somewhere that they were 22#. If I go up to 24# or25# injectors will I need to do anything to the prom. Will injectors from a mustang work? I heard that they are all the same design.

 

22 lb injectors for 5.7.... 19 lb for 5.0..... Yes you will have to get the chip reprogrammed if you go w/ bigger injectors or you're car will run lean, you could get a APFR and try to temporarily adjust it that way, but it's best to get the chip reprogrammed. I have read on the board that people run SVO injectors w/ no problems so you can use mustang injectors.

 

Hi, my Iroc had 19 pound hr injectors from the factory
cuz original engine was a 5.0 tpi (now 5.7)

IM running 9.75:1 forged trw pistons and ford 24pound hr injectors, and an adjustable fuel pressure regulator

Im still running on 5.0 prom, cuz just too lazy

car runs perfect, due to the ability to adjust the fuel pressue,

Im going to update prom, but for now, car kicks *** as is

 

you can get 25lb/hr injectors from SLP for $100 for the whole set. They are LS1 injectors. I put them in my 91z and they worked great.