I got some LS3 injectors for a good price, I purchased these height adapters to go on the TOP side.FUEL INJECTOR CONNECTION - Height Adapter 1/2"

My question is on the orings... Where the injector goes into the intake the stock LS3 injector oring looks to small/skinny.

Does anybody know the correct size oring to make these work with this intake?

 

I'm not sure on those adapters, the ones I used went on the bottom and the injector fit perfectly into the adapter, but I had to drill out the intake for the adapters.

 

These may be opposite of what you need, but I tried... lol

GM LS2, LS3, LS7 Intake Manifold Adapter Fuel Injector O-rings - Lingenfelter Performance

 

These are what I used.

http://www.summitracing.com/parts/fs...FcqZ4AodFigAyw

 

Thanks man, from what I researched the top side adapters were the best way to do it... I dunno.

Bump

 

Dammit, now you have me thinking. I have ls3 injectors from my 408 and those bottom adaptors so they would fit in my FAST 102 and I would like to run them in my 4.8L with an NNBS intake. I'm interested if what I have will work in the NNBS intake. Let us know if you find a solution!

 

I am running the LS3 injectors in a L92 truck intake, same basically as the NNBS, all I had to do was drill out the intake bosses a lil bit to fit the adapters.

 

im running Fast 85lb ls3 style injectors and i used the fast adapters as well but instead of using the orange o-rings that came with the adapters i went down to oreillys and bought o-orings for an nnbs truck and used those with the adapters. fits perfect. the orange orings are too big. this is on an nnbs intake swap on my 04 silverad0.

 

I read somewhere that those don't seal around the adapters, and IIRC I tried them on mine as well, and they didn't fit right.

 

Never heard that.
I bought the injectors off of a member here and he used them the same way on his turboed nnbs.