I know this is a bit of a repost but went to look at and bought a very clean 99 C1500 suburban with 165k and a rod knocking 5.7 Vortec with a fresh pair of reman heads for $850 on friday morning. Had it towed 22 miles for $125. Suburban arrived to the shop at 7:30 pm friday and after dropping a battery into it drove into the shop under its own power albeit sounded like it might throw a rod any second. Immediately my brother and I went to work. Engine was sitting on the stand, stripped to the shortblock by 10:00 pm. Dug the "new" engine out of hiding we had picked up from a 1-ton work van that had blown intake gaskets. It was dressed in TBI heads and had a pathetic stock L31 cam in it. Got to work on it today some. Put a "705" 202/207* @ .050 LT1 F-car cam in it, single roller timing chain 4* advanced, bolted the reman vortecs heads on with a .016" rubber embossed steel shim head gasket and buttoned it up with the ported lower intake and mfi spider from the express. Put a spare 4.3 S10 converter into it and dropped it in this afternoon. All we have left is to get all the accessories installed, source and replace the radiator and heater hoses, fuel line o'rings, fuel filter, pcv, air cleaner, plug wires, plugs, cap and rotor. Have to wait until the dealer opens on monday. Its getting all AC Delco or Delphi parts there. Poor engine probably has a whole tube of silicone sealer on the various gasket. Got tired of them leaking in stupid places like where the dipstick and timing cover meet the block, valve covers, oil pan, and valve cover bolts. Its all siliconed up and I hope I finally have an engine that doesn't weep oil like the Exxon Valdez.






Our buddy Frank is giving us a hand to drop it in and get it running


This was the original post for the L31 and its subsequent use in a 1980 C10 truck. Someone T boned the chevy truck in the passenger door after they ran a redlight. We pulled the whole driveline prior to sending her to the scrapyard.

https://www.thirdgen.org/forums/tbi/...a-350-tbi.html

 

Got to get that beast done though. Friday was a productive day for me. Just got my LT4 heads and LT1 block back from the machine shop for my 1980 Corvette. Also picked up my Titan headers.



Goal is not to make the suburban fast, but give it enough power to not be so outclassed by the newer 4 cylinder economy cars and V6 SUVs. The old L31 should be close to 300 HP and maybe 360 lb/ft of torque, enough to move the thing pretty well with 3.73s and the higher stall converter.

 

That will be tough. My new Malibu turbo 4 puts out 260hp/300tq on stock calibration. Turn boost up and power comes to 300hp/330tq.

What you doing for tuning?

 

Tell me about it! The new 5.3 is 355 hp and has a 6spd auto. The new Chrysler Hellcat SRT8 Challenger has 707 hp and runs a 11.2 @ 125 1/4 mile time on stock rubber.

 

Tuning will be HP Tuners. Already done a few calibration changes. Hypertech spark map from a 1998 C1500 tjat was tuned for premium fuel that I read, raised part throttle shift points and wot to 5,300. Also raised the TCC lockup to 2,000 rpm. Will do some datalogging for VE and MAF tables.

 

I bet those headers could seal with just rtv, lol. Four bolts per tube at the flange! Is this truck intended to be a work truck? Truck motors look funny, the tube coming off the valve cover and the way the manifolds flare out in the back.

 

Everything fast builds is for absolute speed and power. Nothing else. Fast what kinda HP we looking at for this motor?

 

The factory exhaust manifold gaskets are multi layered steel. They actually attach with two studs/nuts per tube. Why they have so many holes in the flanges and undrilled blanks on the heads I don't know.

The tube along the valve cover comes off the manifold and feeds the egr valve in the fron of the intake. I sandwiched an egr delete blockoff plate between the valve and intake and turned the EGR off in the tune.

 

About 300 on the suburban, just a cruiser. We were going to use the shorties we had on the 1980 C10 but can't find them. Not sure if they are in my garage or my brothers or at his shop. When we find them we will toss them on. For now its stock junk manifolds.

 

You know how i feel about manifolds.

Those mani's are going to choke that motor down.

 

I hope he ponies up and adds long tubes or if we can find a set, Thorley Tri-Ys.

 

I thought it was your truck? Long tubes have fitment issues IIRC. Hell shorties do too.

 

Building it for my little brother that is currently trying to get his own new business off the ground. Needed something with alot of cargo space and good towing capacity to tow cars/trucks around. He is going to try his hand at a small shop and mobile mechanic business. Already has two 4.7 engine jobs lined up.

 

Get a life Mike!

 

A good set like a Hooker or Thorley should fit well. The shorties BBK/Edelbrock/Hooker I have installed fit well.

 

Story behind this truck, my brother asked me to find him a shop truck that could be reliable(wanted well maintained 150K or less), have a mechanically simple V8 with decent torque, be able to tow 6,000 lbs minimum, have enough room to transport tools and parts and be cheaply maintained. To me that screamed a GMT400 chassis truck. Budget for the whole truck is $2,500. Saw some running trucks in that price range, but most were beat to hell, needing other work, or 250K+ miles. A pickup truck in that price range was out of the question. Finding this suburban gave us the unique ability to go through the engine, rebuild the front suspension, go through the brake system, change all the fluids and filters, and have something ready to run another 150K with ease. The only questionable part is the 4L60E even though it looks fairly clean and fresh itself but he has a fresh 4L80E on the shelf for the day it dies.

 

Is that the external EGR pipe I see there Fast? The one we've been discussing via PM?

I think you just added to my education!

 

Looks like you got some fans over there at that forum.

 

Yes sir that is the one!

 

Got it to start tonight, but won't stay running on its own. Its the infamous Passkey/VATS junk. Put a noid light on it and get flashes while first cranking then nothing. Going tomorrow morning with my laptop and HP Tuners in hand to reflash the PCM to disable it. Was able to fire it up and keep it running on propane from an unlit torch. Runs very smooth but popped a P1345 code. Will have to perform a crank learns as well. Its all buttoned up minus the hood. The exhaust note is a bit choppier than a LT1 but the air/fuel ratio may not have been quite right.

 

Got a start on it at 6:30 am. Deleted VATS and reflashed the PCM with a 600 rpm warm idle speed and added a Hypertech spark map to it. Fired right up. Was able to set the distributor CMR with a scanner. Then performed a crank relearn and cleared the codes. Starts up and runs smoothly. Sounded pretty mean on its way to the 5,600 rpm fuel shut-off for the crank relearn. Only have a few small things left to button it up and drive it for the first time.

 

Got it buttoned up, checked all the fluids and got a chance to drive it around a bit. Gave it an additional once over, fixed a small coolant leak at a heater hose clamp and drove it a bit more. Just driving it around it runs smoothly and makes good torque, feels about like a stock 5.7 Tahoe/Suburban. When I finally layed into it, the DCLF converter let the engine jump into the torque curve at about 2,700 rpm and the thing took off nicely for a big suburban. Needs the shift points adjusted a little. Bounces off the rev-limiter on the 1-2 shift but thats easy to fix. Definately has the power that I was looking for it to have.

 

You took time out of your life to join our 3rd gen forums just to write that? Credit for other people's work? Oh please, don't make me laugh at you, oh wait, too late lol. Knowledge is passed down from people, we take, add, improve, and continue on. I can tell you that Chris will run tuning circles around you, that is for sure. As for dyno charts, and all that other nonsense being cheered on by the girly mon cheerleaders over there, who gives a freaking crap, the track has the final say in the end, so rather than call him out on the forum, call him out at the track when he is ready to run. Oh, and, about your record holding Nissan Titan, is that record within a five mile radius from your home? I got guys here at e-town that will rape your high 12 seconds with their NA Titans, but could care less about posting on a ridiculous website full of loudmouth idiots, believe it.

 

To add embarrasement, I would run circles around his Titan with the little carbureted 305 in my Vette, much less the LT4 head 383 LT1 that I am working on for it!

The Titan is pretty freaking quick on spray. Not 12.8 fast, YET, but then again its nearly 1,000 lbs heavier than Mikes truck. Mine is 4x4, has all the skid plates and what not of Pro-4X package. Wasn't really mean to go fast and I am afraid to push the transmission that hard. Kinda like this Suburban, just wanted more power for pulling stuff but don't want to kill the 60E. Nitrous was just to play with. If I felt like getting down to close his weight, I would have no issue running with or outrunning him.

I wish this wasn't all my projects. Bumped and ruised my eyebrow on a lift arm while under the suburban last night and skinned a knuckle pretty good while removing the heat shield bolts on the Titan for the headers.

Have a couple of hours of tuning planned for the Suburban tonight. Will put my brother in the driverseat and cruise around for while, capturing data and adjusting the VE and MAF tables.

 

Spent a little more time tuning it and have it running great. Only one issue!!! It is out of fuel at WOT. Stock spider injectors are running 88-90% duty cycle at 5,400 right before the shifts at 5,500. Glad we have not added the K&N cold air intake or the long tubes yet. Not sure we would have the WOT fuel for them. Even if I disable the greatly reduced catalyst overheat fueling I left to protect the cats I fear that it may push the duty cycle over 95% or lean out. The commanded PE air/fuel ratio is stock, save for the 4800+ cells that I have set at 1.17 lambda or 12.56:1 afr. Timing map for now is fairly stock, runs about 25-28* total timing from 3,200-5,500.

Definately not a hot rod engine, but probably makes a solid 300 HP and 350 ft/lbs at the crankshaft, runs just fine for its use. Drives like GM could have put that cam and converter in it from the factory.

 

Tried three different times to get a clean 0-60 video, but was not able to. First time there was a cop camped out in a parking lot ahead. Second time the truck hazed the tires most of the way through first gear and absolutely destroyed them when the power enrichment fuel and timing kicked in at 3,200 rpm, making the suburban drift sideways. If it can light them up like it did on dry pavement, I am scared of what it will do on a rainy day. Too bad the Yokohoma 235/75R15s are almost new because it needs wider rubber on it with a shorter sidewall. The third time traffic prevented me from coming to a complete stop on a flat spot of road. Some other day.

Made a short video for a guy asking how streetable the cam/converter combination was. Being that both are factory GM parts it works very well. Very smooth off-idle and accelerates without excessive rpm or throttle opening. Probably only running 10-15% throttle opening here. If anyone ever gets a chance to tune a GM electronic transmission like a 4L60E or 4L80E, I highly recomeend the BC Trans tool program. Very helpful in getting all the shift tables and TCC tables setup to work with the powerband of a larger cam and higher stall. You can adjust what gears the converter locks in under acceleration, cruise, and WOT. Mine is set for accel lock in 4th, cruise 3rd, and WOT 5th. It will only lock the converter in acceleration in 4th gear. If the shifter is in 3rd for towing it will lock at speed. It will NEVER lock at WOT. Minimum RPM for converter lockup is 1,800 RPM.


Then I had another guy that wanted to hear what it sounded like at idle. Not overly aggressive but if you know the GMT400 trucks well you can definately tell its not the stock L31 in there.

 

Easy fast. You are going to blow that stock trans out of there in a hurry. Only a matter of time before she starts letting go

 

We are actually kinda hoping it will go so we can put a 4L80E into it along with 4.10s and not have to worry about it. With a 4L80E you don't have to worry about towing out of overdrive, just slap the shifter in drive and go.

I only took 50% of the stock torque management out and added 20% to the line pressure in every gear. Also set the commanded shift times to 0.300s for all shifts at all loads. Firmed up the shifting nicely without making it too harsh.

 

In that case i would have just swapped it at the same time as the motor

 

Lol I wanted to make sure everything else was working. That being said I want to put the 92 454 SS 9.5" corporate 14-bolt 4.10 rear-end in it before I swap to the 80E at the same time and swap on a beefier driveshaft.

 

Deleted a few posts... everyone here knows that Fast355 is no liar. Links to other boards having nothing to do with TBI. Come on....

Good info here. Thanks for posting

 

After a couple days of cruising has a couple of codes. Which means more fun hotrod parts to order to fix the weaknesses!

P0430----Bad bank 2 catalytic converter, the ceramic is literally crumbling and blowing out the tail pipe when the engine is reved up. Relatively easy fix!
http://www.jegs.com/i/Hooker/520/2462/10002/-1

http://www.jegs.com/i/Hooker-Headers/520/16532/10002/-1

http://www.jegs.com/i/Hooker/520/21005/10002/-1

http://performance-curve.com/225thun...ter415225.aspx

P1870----The PWM valve is sticking for the converter. Also want to beef up the shifts a little to hold the torque of the old L31. Trans looks like it is newer and has a Serta sticker on it. Probably only buy some time before it blows up and gets a 4L80E and 4.10 geared 454 SS 9.5" corporate 14-bolt.

http://www.summitracing.com/parts/TRG-4L60E-HD2/

I also found a distributor issue I forgot to mention putting it together. The aftermarket world came up with a fix that kept me from having to buy a new distributor. My local Autozone carried it on their help isle.

http://www.dormanproducts.com/digita.../90449_DOR.PDF

 

I know some of you may wonder how this pertains to TBI, but it really ties back to my older post regarding using these Vortecs in TBI cars. Granted I kept the EFI I consider JUNK, its still almost the same exact build I proposed and similar to a build I ran years ago. Just substituted a slightly less aggressive LT1 cam in place of my beloved production LT4 cam.

Just wanted to say this swap can still be done relatively cheaply 8 years after my original post.

https://www.thirdgen.org/forums/tbi/...i-buildup.html

 

My favorite MFI spider injectors are nearly maxed out! 70 psi fuel pressure too. It's making some power.

 

Have I ever mentioned I love a GMT400 engine compartment compared to the G-Van, Express van, Hemi Ram, Titan, S10, and 3rd and 4th gen F-cars it is a cakewalk for any type of work. My brother and I were able to knock out the header and full exhaust install in under 2 hours!!!

It needs an H or X and/or some quieter mufflers soon.

Not tuned yet so this is just a little roll on at part throttle.