I'm going to be installing my TPI manifold and I don't know if I need to install steel block off plates along with the gasket set when doing so? The two square looking plates that actually block off the holes on the cylinder heads. Or do I just need to install the standard EGR block off plate that installs with two bolts directly in place of the EGR valve?

 

No one has done this?

 

I didn't put the plates in when I didn't have a EGR on my old 84. I would venture to guess they just restrict the exhaust gases from entering the manifold and heating it up more. I would leave them out in case you put the EGR valve on.

 

Thanks for the help.

 

Do you have to pass a smog test?

 

My 1990 Jeep came originally with a piggy carburetored inline six cylinder engine. It now has a 350 TPI engine. I'm hoping it will run cleaner then it was ever required too even when it was new. I'll find out!

 

It doesn't matter if it runs cleaner than the 6 banger, the rule is it must pass the emissions for the engine, but older engines in newer vehicles is not allowed. An 87' TPI will pollute more than a 90's 6 cylinder.
I assume you didn't go to the expense of retrofitting rhe 70's block with a roller cam and lifters.

If they do inspect under hood the TPI will stand out like a sour thumb in a Jeep.

Let's say the Smog Tech is not so bright, and you removed the SES/CEL bulb, but the analyzer will still detect high Nox because you disabled the EGR.

 

Well that's not good.