I bought a 2013 Silverado intake manifold because I thought it is a NNBS, and the internet says that a NNBS manifold is the same as a TBSS manifold.
So will the fuel rails and other stuff that I can't think of from this rectangular port manifold work on a TBSS manifold?

 

I'm running a square port L92 intake on my setup and we used aftermarket fuel rails and made it a return system. When you say rectangular I'm guessing you mean cathedral.

 

I have cathedral port heads and this manifold has square ports

 

Better off using what GM labels them

GMT900

 

Actually rectangular, running same intake on my 99 and you need fuel rails for that intake or aftermarket!!! The injectors go in at different spots onthe intakes which in turn moves the bolts to opposite side of the rail, if you have cathedral port heads you need a cathedral port intake.... The rectangular ports i do believe are taller than the rectangular ports....

 

L92/l99/l76/ly6/ls3 are rectangular ports ls7 and i think ls9 are square port and 4.8/5.3/5.7/gen 3 6.0 are all cathedral... The cathedral ports come to a point at the top....

 

So a TBSS is not the same as a GMT900 manifold? There are no manifolds that are the same as TBSS because the TBSS is the only GMT 900 style manifold with cathedral ports?

 

So if I want a TBSS manifold, it has to be off of a TBSS?

 

The 07-up 4.8/5.3 manifolds are same....

 

If memory serves the tbss had 243 heads which are being used on 5.3s now....