I need a center iron for a TII engine. I have a stack of NA irons but none from a TII. The engine will be street ported so the stock port difference is irrelevant as well as any differences in emissions ports. Shouldn't be a problem should it?

 

Check that. Found a nice S5 NA iron in my stash. Saves having to plug the EGR port. Visually they appear identical to the TII iron. I understand the casting around the closing edge of the port is different. Other than that?

 

Isnt there a bolt hole missing in the N/a iron for the manifold? Right above the runners?

 

Good call! That's easy enough to take care of. Anything else?

 

i think thats it. ive done t2 iron in an na motor, we made no changes to the iron and it worked fine.

 

I machined the center iron for the extra bolt. Assembled the engine Monday and will have it in and fired by the end of the week. So far everything looks good to go.

 

Here's a pic of the finished product...

 

looks good! that reminds me though, just for the record the oil filler pipe is different

 

I've gotten ito the habit of using NA TB necks on the end of turbo intakes when building custom IC plumbing. This is another on of those cars. The only issue with using the NA neck is that it runs right across the stock oil filler. Easy enough to pop it out, cut it up, and weld it back together for clearance.



Kinda like this...

 

Fired it up today with no issues. So I guess the final answer is, if you want to take the time to cut some threads for the intake bolt, the NA center iron works just fine in a TII.