LM7 383 Build Up

[bangbangskeetskeet]

If I was to go with a 90mm intake which manifold and throttle body would I want to use? I don't really want to get into anything super expensive like a FAST, but are any of the other GM truck or car manifolds and matching throttle bodies that would fit the bill with out modification to the throttle body wiring, etc?

On the note about the longtube headers. Wouldn't having longtubes throw codes on the computer and also decrease my mpg because of having no cats? I am trying to keep the truck emissions legal. They don't do any visual checks in WA state, just plug in the code reader and make sure you don't have any codes. I have no experience with long tube headers on fuel injected vehicles so the input is greatly appreciated.

Yeah the TBSS comes with a 90mm TB and is also a good upgrade for the intake manifold. Depending on what year you're dropping this motor into you will have to fab a bracket if you're going to do a cable driven TB or either repin the PCM for a DBW TB or get the x-link...I haven't had any experience with it just heard about it.

Another option if you didn't want to go through that trouble you could just get an 80mm or 85mm DBC TB and have it ported and polished. Granted it's not a 90mm but it's still better than the stock 78mm unit.

As far as the longtubes that's ehat a tune is for. With the proper tuning the codes that would be set off by not having cats or the rear o2's are essentially turned off in the tune. I run the Pacesetter LT's and ORY with no cats into a single 3" in/out flowmaster and I have no codes and get about 17mpg on an average tank of gas. As far as getting better milage with having cats...I personally hvent ever heard that and honestly dont believe it. The cats are really just a restriction for the exhaust to flow.

Edit: You had also said you didn't want a higher rpm cam...the LS6 cam is exactly that. It makes power on the higher end. I am going to be installing one in my truck and will be shifting at 6300rpm. You really should look into a little larger cam or get a custom spec'd cam from someone.

[blackout]

Its a dbw throttle body no cables.

so what year of TBSS intake and throttle body would I be looking for if I was to go that route?
or
suggestions on a ported stock style throttle body? BBK? (do ported TBs or like the BBK 80mm style need the manifold to be ported?

Thanks,
Ty

[thArf]

i have 6.0 injectors layin around if you need em

[blackout]

i have 6.0 injectors layin around if you need em

I appreciate the offer but I already got some 44lb Racetronix Injectors.


So if I was to port my thorttle body or have someone port it for me, would I need to port my intake manifold? I have been looking at the Xtreme EFI unit.

link: 2003-07 Vortec 78mm bored throttle body 4.8L 5.3L 6.0L:eBay Motors (item 370290379647 end time Nov-24-09 09:09:00 PST)

I would like to use my stock intake with a ported unit if possible seeing as though as soon as you step up to something bigger you need to spend exponentially more money. But I am concerned about the engine getting enough airflow. Would a ported unit such as this supply enough air to this engine setup? I think the LS6 throttle body was only like 75-80mm? (not 100% sure)

Thanks again for all the help guys!

[SLO TRUCK]

Pretty sure the stock TB and Intake are fine Farmtruck made 800hp while using them. I am sure you will be ok with them unless you just want to change them

[blackout]

Pretty sure the stock TB and Intake are fine Farmtruck made 800hp while using them. I am sure you will be ok with them unless you just want to change them

I definitely don't want to get into an intake swap as it seems pretty involved the more and more I read, just a lot of people hopping up truck motors do like the TBSS swap. But you think I would be ok on a stock intake manifold with maybe some TB porting on my 383? what do people use when doing 408ci or other such motors in trucks?

Sorry for all the questions, I am a TBI guy and this is really complex and new to me.

Thanks!
Ty

[pl4yboy]

I definitely don't want to get into an intake swap as it seems pretty involved the more and more I read, just a lot of people hopping up truck motors do like the TBSS swap. But you think I would be ok on a stock intake manifold with maybe some TB porting on my 383? what do people use when doing 408ci or other such motors in trucks?

Sorry for all the questions, I am a TBI guy and this is really complex and new to me.

Thanks!
Ty

Intake swaps aren't as bad as they sound. The 78 will probably be fine, but the 90 will make more power of course. It's all up to you. Most people running 408s have upgraded to the TBSS or NNBS intake.

[blackout]

I have been reading about having to get a certain corvette fuel filter (wix #33737) to convert the return fuel system to a returnless fuel system and having to mod the pcv on the pas. side somehow. It seems a little overhelming.

anyone have a link to a write-up on the TBSS or NNBS intake swap?

[blackout]

well i got good enough info from one of the members over on performancetrucks.net to do the TBSS intake swap. As soon as its all done and running I am going to post a complete swap thread with part numbers and pics, etc.

[txarkitekt]

Dang Ty--you have learned a lot so far. For the most part, every one on here has given good advice.

The TBSS intake with 90mm TB will be a welcome addition, but not needed. A truck intake with a Shaner PnP TB would have been fine.

The LS6 cam will leave you saying, "I wish I had a bigger cam." AND NO RE-GRINDS! Re-grinding a cam removes the heat-treat on the lobes and makes them soft and more prone to failure. A good cam for your build would be a 218/224 .563/.563 113+3 LSA.

Good luck with it all.