I'm the kind of guy that does far too much research and not enough action, but I want to put all my questions in one thread and try to get as much info out of you guys as I can. I've done some reading and some searches, but theres some crap I can't find or just want to confirm. Thanks in advance.

I want to install Longtubes with TD's, looking into keeping cats on it (no sniffer test but inspections, and it is a DD). While I am down there I want to take out the EGR and AIR crap, as well as do an OTVC setup.

This is the setup and incomplete parts list I have built so far,

-Coated Pacesetter Race Headers
-3" to 2.5" reducers
-Stainless Steel X Universal 2.5" X-Pipe Kit (see below)
-Stainless Steel 2.5"x18" Sweet Thunders (these are the mufflers in the GMMG correct?)
-Hangers
-Turn Downs

-Cats of some kind (see below)

-MSD OTVC Wire Kit
-NGK Spark plugs (TR55 are the factory replacements correct?)
-o2 Extensions
-LT4 knock module
-160* thermostat
-DEI HeatTape fuel lines and any wires close to the headers
-EGR Block off plates (cheapest place to get them?)
-AIR delete parts? (see below)

-Mail Order Tune some time before the next OBDII test


Here are my remaining questions,

-Do I need any specialty parts to take out the AIR system?
-Which spark plugs are the stock replacements? Are these what you guys recommend for a bolt on car? What are you guys gapping them at?
-I do not need rear o2 sims or anything correct? They just throw a code but wont **** up the pcm or anything like that right?
-What are some good high flow cats that aren't like $200 a piece? Would you just get some cheap 2.5" ones and gut them?
-These are the two X-Pipe kits I am looking at because of their inexpensive price and Stainless construction

"DS Tunnel Style"
http://www.pysales.com/iwwida.pvx?;i...0%201?comp=ppe

"Standard"
http://www.pysales.com/iwwida.pvx?;i...0%201?comp=ppe

Which one would fit better, and would anyone advise staying away from Pypes or have a good alternate?

-Realistically what should I expect a shop to charge to weld all this **** together?
-Any other misc things you would do while down there?


I really appreciate any help I can get. I only want to do this once

 

When you get your tune have them
-tune out rear O2 sensors
-tune for LT4 knock module
-tune to run 160* thermostat

Nothing will happen if you drive with rear O2 sensor off.

When you remove EGR and install block off plates, you will get a code have them remove it in the tune.

The AIR system comes right out you dont need anything else after pulling it out.

I paid about $140 to have all my true dual X-pipe weld together.
Tell the shop not to weld the long tube to the X pipe that way you can remove it anytime you want.
I used band clamps and no leaks at all.

 

I was looking into gaskets and what not, would you recommend Percy manifold and collector gaskets? They seem to be the real deal. I definitely don't want the exhaust welded to the headers, would band clamps eliminate the need for collector gaskets?

What about bolts? I really don't like the idea of the T8's seems like way too many goddamn small parts and what not. I read ARP bolts are good, but I couldn't find a place to buy them

 

Just saw an ad for the Percy bolts in GMHTP. Will be replacing mine with these over the winter probably.

 

When I looked on Summit they didn't have the Percy Split Locks for LT1's, just LS1's and I think SBC, I don't suppose either of those would work would they? Or have to released an LT1 bolt?

 

ARP sells stainless steel studs for headers, but its quite expensive 80$ I think.

Drop by your local department store and take one of the old bolts with you, get a grade 8 bolt and if ever possible, a 12 point headed replacement. You avoid slipping the socket and rounding out the heads.

Also make sure to apply anti-seize to the threads before you install them back on.

 

I talked to a reputable shop here in Tacoma, they quoted me at $500 for labor to weld up the exhaust. Now, they do amazing work and it would be TIG welded but I can not afford that by any stretch of the imagination.

 

500 to weld up dumped TDs is insane. and fyi sweet thunders are not what GMMG uses. they use their own chambered muffler.