Are any spacers needed *at the bottom* where the injector itself seats into the manifold? The tips of the ID's protrude further down than any other Bosch injector I've seen. While researching fuel rails I came across a thread on YB where a guy said he had to use spacers:

Truck intake and after market fuel rails - Yellow Bullet Forums

 

Which ones are you using and what length are they?

The 1000s don't need any spacers nor should the tip matter. The Bosch 127s I had came with a tip that was like 1/2" long and would protrude down into the runner

 

They are the standard 60mm long, same dimensions as a factory LS1/ LS6 injector. The tip is about even with the gasket plate.

I'll need to fab brackets for my Holley rails, not a big deal there. I'm unsure if I'll have room to go under the t/b for the crossover and whether the 90* coming off the rail will clear the alternator. I've read mixed reviews about this.

 

I have a 180 clearing the alt. Just trim the plastic backing cover.

 

I was hoping to go 90 out of the drivers side and underneath the tb to the passenger side then out the rear on the passenger side to the regulator.

 

Going with the crossover over the TB will probably be a better bet than under.

 

You mean to avoid heat soak or just for space?

 

Space