I started my head swap on my 1987 L98 350 motor with TPI. I knew I was going to need to modify the four center intake bolt holes on the TPI intake but I did not expect to see an exaust port in the center of the old heads.
I am sure it is to warm the intake and I see there is vacuum valve and a sensor mounted to the port on the TPI intake. My new Aluminum heads do not have a center exaust port. Does anyone know what I am in for if I block this port? Any help would be appreciated.

 

Your EGR won't work.

If you found an '85-'86, or Vette base, that would solve your mount bolt hole angle problem.

 

Thanks for the reply. When you say my EGR valve won't work what does that mean? Does that cause the motor to run rich when cold and not idle or will the computer adjust for it? I also was thinking of running a 1/2 tube from the header to the intake if needed. I can modify the intake bolt holes with no problem.

 

Back in the days of carburetors they exhaust crossover heated the plenum under the carb to help with cold engine fuel atomization. When they went with TPI the only thing it does is supply exhaust gasses to the EGR valve (emission device).

Unfortunately, the ECM knows if the EGR system has been defeated either by removing the valve, plugging the vacuum lines that run the valve or just blocking off the exhaust crossover passage like you've got with your heads. It will throw a check engine light.

The only right way to get around this is to turn off the EGR system in the chip programming. Or get a different set of heads with exhaust crossover ports.

 

Thanks Damon for the info. So it won't effect the way the engine runs. Who could I talk to about chip reprogramming? Can I purchase the proper programmed chip?

 

I think I found the answers in some old posts. Thanks for the posts it pointed me in the right direction. I would still like a source for chip reprogramming though. I would not think of taking on this project without this site thanks to all that share their know how.

 

If you're not doing any major modifictions to your motor, like a bigger cam or larger injectors, and you simply need the EGR deleted in the chip, you could talk to tpiparts.net. They won't burn a perfomance chip, but they offer basic chip reprogramming services for a really reasonable price. They can delete EGR, get rid of the speed limiter, program for a 180 thermostat, lower fan turn-on temp, etc. For a high-performance type chip you'd need to talk to Ed Wright at Fastchip or PCMforLess. Of course the cheapest route is just plucking the "check engine" light out of the dash. The car won't run any different without a functioning EGR. You can always put the bulb back in and use a paperclip to jump the A-B terminals of the ALDL connector if you ever need to check for other trouble codes besides the code 32 for EGR.

 

Thanks for the contacts Pat. I'm thinking I will need to get a chip burned, I am adding Pro comp Aluminum heads, hooker shorty headers and roller rockers. I was already running a Comp roller cam a 180 stat and a low lower temp second fan switch 3.73 gears and K&N air filters. Spent 12 hours working on it today and looks like the push rods I bought are about a 1/2" to long. Back to the store. Also found out my cat converter was broken into pieces inside and had to gut it.