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    5.7L Vortec Catalytic Converter Question

    4.3/5.0 L35/L30 had single cat like TBI 4.3/5.0/5.7, but Vortec 5.7/7.4 had dual cats. The LD and HD 5.7 L31 trucks also had different pipe sizes off the manifolds 1-7/8" vs. 2-3/4 for the over 8600pound GVRW trucks. peace Hog
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    5.7 Vortec cold tap/knock HELP!

    I had 1/2 a dizzy gear worn almost to breakage, teh gears were knifedged badly, very sharp. Common issue, my engine had 58,000km when it required a new dist gear. It'll be in your hands, easy to look at. You'll never be able to get your distributor base installed in the same exact orientation...
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    7.4 Vortec k2500 Exhaust Manifold/ Header Install

    3 heating and cooling cycles will loosen anything. IF you can get the heat where you need it. You are attempting to breakup the threads via dissimilar expansion rates. Heating the cylinder head by running first could be detrimental, rather than heating the stud leaving the head cool. Always...
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    96 Vortec fuel pressure

    Pressures on the Central Sequential Fuei Injection(CSFI) is 60-66psi, pump running. This is the base fuel pressure after which the vacuum referenced FPR pulls down fuel pressure when manifold vacuum is high, like when idling. Basically a VRFPR keeps the pressure differential across the injector...
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    Ac isn’t cold at idle

    Underdrive pulleys can make the issue of poor stoplight A/C performance worse than OEM. The OEM GMT-400'like trucks in addition to the mechanical fan also come equipped for an "Aux. electric fan as well. Control for the AUX. fan is in the L29 calibration. Even bumping the idle rpm a hundred...
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    stalled when trying to restart starts cranking normal then acts as if timing way advanced

    What happens if you remove the air intake and drizzle fuel into the throttlebody while cranking? I once used this technique to back a truck with a bad pump into the shop. If the truck fires, you've got some fueling issue somewhere. If this is a 96+ L31 Vortec 350 the fuel pressure will be...
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    Stainless Shortys for 1998 K1500

    The main issue with the OEM manifold to catalytic pipes is its diameter and the nasty crimp style bends. Now your 305 L30 will have the TBI 305/350 Y-pipe and single cat. Upgrading to dual cats with better headpipes would work nicely. Here are the 1/2 ton L31 and 3/4 ton L31 headpipes side by...
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    4.3??? Would like to know more about it.

    I had a 1992 regcab shorty TBI 350 C1500, 3.08 open rear dif, full lo9ad Silverado. My girl had a 1997 200hp L35 V6 reg cab shorty 4l60e 3.08 rear gears open dif. We would go to the drags and whjile my LO5 350 V8 would always rip her V6 out of the hole, that L35's top rpm power and lighter...
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    1998 K1500...5.0 wiring vs 5.7 wiring?

    The 4,3 and 5.0 have 3 precat O2 sensors, while the 5.7 and 454 have 2 precat and 2 postcat O2 sensors. A Bank1 and Bank 2 precat then a Bank 3 precat sensor which reads BOTH Banks at once, then the single aftercat efficiency sensor. There are some differences between the 1/2 ton 350 and 3/4 ton...
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    Vortec to Carb swap

    These controllers are expensive. You could always go manual valvebody and use a vac-mod setup to control line pressure. peace Hog
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    Jet programmer for 96-00 l31

    Its basically Tunercats OBD2 except that there isn't unlimited tuning, you have to pay $100 for each VIN license. There is little if any support, so as TC2 its geared more towards experienced PCM recalibrators. If you cant get a copy of TC2, Jet does work it uses JCL.files IIRC. peace Hog
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    Hooker Competition Headers

    Here are some pics of the 1/2 ton 1 7/8 crimp down headpipes next to some 3" 3/4 ton L31350 pipes. I have the Hooker Comp Series 2462 1hkr headeres with 1 5/8" x 2 1/2" headers. The 2806 1hkr with 1 3/4" x 3" collector Supoer COmpetition series use equal lenth primaries, but are twice the...
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    Vortec Tuning

    You canty use the Tech 2 to tune them, but you can use teh TECH2 for boidirectional contyrol of teh trans, TCC aBS etc. You cant actually make changes to a calibration with Tech 2, but you can use Tech 2 to load a calibration into the PCM. peace Hog
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    GMT400 History

    I'm pretty sure you couldnt get a 4.10 gear in a GMT400 with the 10 bolt. You may have been able to get a F44 14 bolt 4.10 ratio like the 1991-93 454SS, but with 6 lug axles. peace Hog
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    305 = 454 swap

    The 7.4 will bolt right up to your 60e, the bellhousing pattern is the same, just like any other GM engine. You will need to use the flexplate that will fit your 60e's TC. peace Hog
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    Automatic high idle

    GM used idle control in the LP4/L21 engined trucks. Since these trucks only came with the 80 pin x 2 connector 512kb PCM's, I doubt this will work on the blackbox trucks as the L21/LP4 trucks also run ETC. Swap to a 896 or 411 PCM, swap over to CNP and ETC along with an L21/LP4 calibration...
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    Anybody running the 290hp GM crate with their Vortec MPFI?

    X2 I concur. Dont be fooled intop thinking the 330HO is special. Its a derollered L31. peace Hogg
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    Banks monster exhaust

    Banks used to make the best headers in the world for the GEN 1 and GEN 1E SBC. The flanges were like 5/8" thick, gaskets werent needed. I would love to have a set. They also make some cool headers and exhausts for the motorhomes. peace Hog
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    Identifying junkyard 6.0 liters

    Ya, its an issue if the vehicle or VIN is unavailable. You are correct about the pull the plug, try and feel the dish of the piston for the LQ4, flat tops for the LQ9. If its a 6.0 from a 1500HD, 2500, 3500 its an LQ4. Sierra AWD C-3 and GMC Denali pickups use the same LQ4 but are rated at...
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    LSx swap with AFM?

    I agree, a complete engine/PCM retrofit would be in order. The 411 PCM can't control an AFM/DOD application. Threads- LMG flex fuel AFM into GMT400-style Hoe http://www.pacificp.com/forum/viewtopic.php?t=6034&highlight=lmg&sid=1f619b3009af3749d3936c19081dff06 And video of the same project...
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    LQ9 Swap into my 96 C1500?

    I would way rather have the gearing of the T-56 than that 6 speed automatic. The rpm drop between 1st and 2nd of the 6l80e/6l90e trans is even larger than the wide ratios of the 4l60e/65e/70e trans. The best stock auto trans that GM ever built in regards to gearing is the thm-200r4. It has a...
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    Installing GEN3/4 engine in front of older 4l60e and vice-versa

    This is some valuable info for those of you who wish to install a newer GEN 3/4 engine in front of an older 700r4/4l60, 4l60e. Also info for installing a newer 4l60e/4l65e/4l70e behind a GEN 1 TBI SBC and GEN 1E Vortec 305/350. This is from a post I created over at PPE...
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    Engine questions

    If you dont want to set of theknock sensors, stay away from 1.6:1 full roller rockers. Fulll RR's are noisy and the knock sensors will report the noise as engine knock to the PCM. If you dont modify the tune, the PCM will start pulling timing thus reducing power. The GEN 3/4 engines use...
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    need a question answered...

    You just swap 2 pins and retune the PCM so far as the electonics go. They are both 4 speed OD transmissions that are controlled via the same PCM. peace Hog
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    How to get Coil per Cylinder and LSx ignition control on a L31 SBC Write up

    The actual sensor is from an L21 truck engine, the reluctor wheel is copied from a 24x reluctor from an L21 truck engine as well. Both of tehse parts are installed into a Vortec 305/350 front timing cover. peace Hog
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