|04-01-2017 05:57 AM|
Avoid the 99-00 engines, esp the LQ4 with iron heads.
Use a 0411 PCM from and GM vehicle, and flash to a 2001-2002 Express Van calibration. The 01-02 Van uses the newer 512kb PCM along with the older 4 x reluctor 305/350 engine and uses Vortec crab distributer.
Buy a 24x reluctor wheel from EFIConnection and use a Corvette LS1 calibration on a Vortec 350 in order to eliminate crab distrivuter for high tension usage, (only required for 1x CMP(camshaft position) sensor, Electrobic Throttle Control and to drive the 8 Coil Near Plug(SNP) coilds
Buy 24x CKP(Crankshaft Position) sensor, use LS1 Camaro/Firebird calibration as ituses cable driven mechanical throttle and CNP ignition.
If you wat to swap from CSFI(Centralport Sequential Fuel Injection) in the 1996-2002 L30 or L31's you simply cut off the stock injector harness and spice in the 8 pinkl grounds and 8 colour coded harness wires into conventional fuel rail fed TPI/LT!/LT4/LS1/LS6 fuel ibjectors in a Vortec style EFI intake manifold(Ramjet 350 or TPI/Vortec conversion intake Marine Intake or a Shoebox with 8 injectors and a throttlebody would work)
Its all in here
GM Performance :: View topic - Vortec L31 MARINE MANIFOLD project! Q&A
I see the term 400 hp L31 thrown around. Its not a simple bolt together deal. The best N/A numbers have see on a Vortec 383 with Vortec heads tat have been home ported were 330hp/381 rwtq. The same setup on a 350 shortblock was 305 rwhp. This was with a 218º/228º Hotcam.
Yes 400hp can be obttained, but itdoes require custom tuning and a well thought out plan with regards to induction and headers/exhaust.
Jere is our 0411 PCM swap thread. Just PM Lextech, with the the year of your GMT 400 truck(96-00 Vortecs) with a working email address and he will send you a full 0411 conversion pinout sheet, each year truck requires a specific sheet. He can also supply the connectors and even a 0411 PCM with a basic startup tune setup for whatever injectors you want to run.
If you go to the PAcif Performace forum and PM lExtech, he'll get back to you. That's a great site for everything Vortec 305/350. The Marine intake and 0411 PCM swap were both our creations.
|03-29-2017 02:54 PM|
I am starting the search for an engine
Lot's of great info here. I am leaning towards the LQ9 I think for a couple of reasons. One, we have a pull a part close and seem to get a lot of Caddi's in there, more so than trucks as well as the performance of the engine.
The LQ4 is a strong contender as well. The LS1 should be plentiful at the local yards so I will keep my eyes open for those as well. I have looked online and found many swaps parts available including instructions or videos to help guide me.
I am not to (famous last words) about the wiring, I will find an engine with the pcm and all that I need to make the swap. I do wonder where I can get the pcm re-programmed, any ideas?
as always, many thanks,
|03-19-2017 06:02 PM|
There is more than one way to skin the cat. The OBS trucks are not intergrated like newer trucks are.
One way is to splice in an 0411 PCM into the OBS truck and find and adjust the wiring to the engine/ trans as needed. Many temp or sensor connectors are the same. That's the way you can make it look totally factory if the connectors are re pinned, rather than cut/ spliced.
The easiest way, would be to buy or build a standalone harness for the engine. They really hook up to power with 2 or 3 connections once they are modded and programmed for standalone. Place the OBD connector where it was originally ( the trucks mount the same ) and wire the gauges up. Need to read a diagram or 2 for wire color but, they are electrically identical. The original PCM won't do much at all but complete the trucks electrical system, and the standalone will run the engine/ trans..
I would go for a '99-'01 engine as they were still cable throttle.
|03-19-2017 08:01 AM|
The OP mentioned this is in a K1500 - 4WD just adds onto the expense and fabrication.
|03-18-2017 07:17 PM|
|bullheimer||funny, i was thinking, about the same thing but now that i read Comptons post 2, i can think about something else.|
|03-18-2017 04:17 PM|
|matt167||The 6.0 is the one everyone wants. They will bring the most. The 5.3 is probably the most popular due to coming in more trucks. And the 4.8 is the one that is dirt cheap. They are regarded as black sheep but, they make more power than the 5.7 vortec and will get better mpg. If your truck is a 5.0l its even better.|
|03-18-2017 02:30 PM|
I am hunting for a nice 5.3 vortec now. I have on in my 04 Tahoe. It has 258,000 miles on it. I have used synthetic oil since day one and still has a oil pressure over 40lbs after warming up so I am tempted to pull that and rebuild it. My wife may not like that idea lol, so the hunt goes on!
|03-17-2017 05:02 AM|
|matt167||Ls based engines into obs trucks have been done and are a great idea if your up to the wiring. The mounts need adapters but they fit and bolt in. Fuel pumps are good enough, and the gauges will work with the ls. But you have slight issues with things like the ac pump and the fact you need a full ls harness from engine you use for a standalone system.|
|03-16-2017 08:40 PM|
im kinda in the same boat with a '97 c 1500 scsb. wanting more than the 5.7 can pump out. i looked at a 5.3 conversion and there are tons of threads/previous conversions out there. you need to swap the PCM as well. I think Painless (prolly others) make plug n play harness as well lots of engine mount, trans mount/adapters as well accessory brackets. prolly need to swap out the a/c if you want to keep it with a custom bracket or notch the frame.
Personaly, i chose to pick up a blue print 383 with 1.6 rockers and work the stock intake. there are aftermarket mpfi injectors (i have a 36lb set up going in). ill port the bottom intake to help (still have the mess called spider injector harness to jack up flow). taylor makes a 1" spacer to go between the upper and lower intake to help the flow. i think i can flow plenty to support the 350ish hp. with larger injectors i feel this would support over 400hp. blackbear tuning and i think ill be on the road to 4l60e destruction soon
|03-15-2017 07:17 PM|
The 5.3 like all LS engines lacks a distributor. Your 96 has and needs one but its rather unique in that the classic guts aren't in it, the computer is calculating the advance rates.
I found this LS distributor adapter and went ah-ha till I found it mounts a Ford rather than Chevy distributor.
I'm not sure that this a Ford distributor that works the same way the L30/L31 does but if it does and will interface electronically all you need is money.
Another way to skin this is with a stand alone LS ignition controller, I'm off the map of things I have done here so I'm supposing that if the controller supplies a tach signal which I'm pretty sure it does and if you feed that signal back into the original GM computer that it will satisfy the computer's view of the world that the engine is running correctly and will fuel it and operate the transmission correctly.
Goes back to what I first said is that when you start crossing these design generations it gets complicated fast and that usually leads to costly in terms of time and money. Not that it can't be done but it becomes a race between the finish line and your credit limit as to which you cross first.
|03-15-2017 06:28 PM|
Vortec 5.3 into my 1996 1500
First, I want to thank everyone for the great threads you posted. There is a lot of good info there.
Now I am asking myself, should I just go with a 350 and build it a little? I was told as long as I stay under 1999, a 350 is a easy swap. I could build a little pep into it with head work, mild cam and such. Do you think this is a better choice? I am not looking to put 400 hp to the rear wheels, just something that will get out of it's own way and be fun to drive.
|03-15-2017 05:51 PM|
|BuzzLOL||Wonder if that MPFI conversion setup can be ordered out with 450 HP injectors!|
|03-15-2017 05:29 PM|
Here's a couple things :
1) This is a conversion actually developed by GM for California vehicles where the CSFI had failed. These are a special designed high impedance injector made to fit where the original pressure valves were installed in the manifold. This shows in a hot-rodder sense that the original injector drivers in the computer box can drive a manifold mounted HI injector.
Vortec CSFI to MPFI conversion
2) Going beyond that I recently made a discover of what I was taking about which was to use a conventional manifold dual or single plane with injector bungs, a Throttle Body that mounts the necessary sensors, driving the injectors off the factory computer. This would use high impedance injectors more of the TPI style than the GM California L30/L31 fix injectors. This unit is from Racing Head Service but is quite representative of what I have in mind.
Small Block Chevy EFI Single Plane Intake Manifold w/ Fuel Rails - Intake Manifolds - Intake Manifolds
|03-15-2017 03:05 PM|
|03-15-2017 02:56 PM|
X2, what more can I say?
To the OP:
It costs a lot of money when you get into these generational changes especially if it has to SMOG. Not that it is impossible to do but the detail changes in the systems takes a lot of time and similar amounts of money to work out.
Unfortunately the injection system on the 96-2002 Gen I Vortec sucks. On the good side is the computer in those will drive the earlier injectors which means with a change to a conventional carb style manifold with injector bungs and a throttle body; the L31 can be converted back to something more like TPI. This gives a better intake than the TPI or MPFI engines with better injectors than the CSFI. The earlier injectors are now operating sequentially. This allows engine mods with various methods of reflashing or external processors, there for the sensing and drivers for the other systems are not affected and except for engine power and transmission control everything else from security to tank venting continues on as usual. These mods easily make a 400 horse 350 under L31 heads. While messing around you might want to consider a 383 kit, it's no more expensive than a standard rebuild and the difference compared to a 350 is like a different universe.
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