opinions on my LS swap setup

first off im new to the LS world but im no stranger to building franken-vehicles. im working on swapping a 6.0 LQ4 engine from a 2006 express van into my 1981 C10. its going to be backed with a 2WD colorado 5 speed transmission using the fabbot AR-5 to LS full conversion kit. Engine wise i have a texas speed BFD chop monster 6.0 cam, BTR .660 valve spring kit. This engine was stock with 317 heads. i also have a set of 706 heads from a 5.3 in the junkyard. from my reading the 706 heads will raise compression some and provide low RPM torque but lack on the top end. would the 706 heads technically conflict with the TSP cam? basically im just putting something together to cruise around town, take to shows occassionally and do big scary burnouts. i do have a notion to put a turbo on it but thats not in the budget right now. i know the 317 heads work best with a turbo so i would be saving them if i ran the 706 heads for now. for the time being i modified the stock exhaust manifolds by welding 2.5 in V-bands where the original 3 bolt flanges where. game plan was to step each bank up to 3in after the V-band, make an X pipe under the truck or get a muffler thats basically an X pipe and dump the exhaust in front of the back tires. stock manifolds look like they should flow pretty good for now plus i see the turbo guys modding them with no complaints. in the future i was looking into getting a trailblazer SS intake manifold but that involves converting to drive by wire. im wiring the truck with the engine harness from a 2000 silverado parts truck. i have reconfigured the harness to match up with a blue/green 4.3L blazer ECU since its the ECU with the larger 1MB flash, more features than the blue/red, and the 4.3 ECU has the hardware to support both drive by wire and drive by cable. i flashed the ECU with 12587603-2004-Corvette-M6 software and base reconfigured it with HPtuners to be compatible with my setup. why that software? well some kind person out there did a very good code disassembly of this firmware as im an ECU nerd and will be writing custom code into the ECU for things like launch control, hard spark cut RPM limiter, flat shift and whatever else i dream up. i will be running it with HPtuners speed density conversion too so i fit a 4.3L blazer IAT sensor in the intake manifold where the EGR solenoid was right after the throttle body.

on the rear end i have one from a 2000 silverado thats supposedly factory limited slip. would be nice to have the rear disc brakes plus upgrade the truck to 6 bolt so i can run modern wheels that are more readily available. im not sure what i should do in the front. i was staring at the 2000 silverado's front spindles and it would be nice to just use that trucks whole spindle because of how the front brakes attach. the OG spindles have the carrier built in which is no good for me as i have a rather large set of brembo 4 piston front calipers that i could fabricate a carrier for based on the 2000 silverado's front spindle since the factory carrier is removable. is it possible to retrofit the 2000 silverado front spindles to the 81 C10?

good suspension stuff isnt in the budget right now so i will probably just flip the axle in the rear and block it than figure out something to get the front end down. looking to get a 5-6 drop on it. plan is to get all QA1 stuff once funds prevail including their 4 link rear end setup.

am i on the right track here?

Thumbs down for mating a 6.0 to a Colorado transmission unless there's something I don't know about.
Thumbs up for spelling axle correct.
We're gonna need pictures of this Frankenstein.

I did the LS thing a few years ago and it's by far the best thing you can do to these trucks. Here's what sticks out to me:

- A) Pick a better cam. That cam sucks in a heavy truck. My buddy's got it in a suburban and my god is it a dog.
- B) The 706 heads are a good choice to bump compression. They won't hurt flow (unless you're turning it 7500+ and then any OE head is going to be limited)
- C) The only way to know for sure if your cam will work with the heads/not have PTV issues is to check PTV yourself. You can also talk to Texas Speed and they can give you a rough yay or nay but the only way to know for sure is to check it yourself
- D) That AR-5 isn't going to last long if you plan to beat on it. Drive it nice and hopefully never hook up, with a good clutch and you'll be ok. I have a Vengeance Clutch dual disc in mine with a T56 and it's awesome
- E) Stock truck manifolds don't clear the frame. Get headers or the Hooker manifolds
- F) You should already be drive by wire being an '06 engine. The TBSS intake is a good power bump on any LS
- G) You lost me on the computer side. I used the donor Envoy E40 computer that came with my engine and my buddy/tuner tuned it with HP.


For the suspension, you're going down a rabbit hole nobody else has been. Also, there are literal thousands of 5x5 wheels, there's no benefit whatsoever to go to 6-lug. Most 6-lug guys with the older trucks convert to 5-lug. Also, that 2000 Silverado rear end won't have the correct mounting pads or anything to mate up to your leafs most likely. Not to mention it'll have the GM "Gov-Loc" that is not at all desirable (it's called a Gov-bomb for a reason) and a terrible rear disc design that never works well. I would highly suggest just using your original 10-bolt and building it up (I did mine with 30-spline stuff from Quick Performance that should be good through 6-700hp) or pick up a 9-inch from QP that's set up for these trucks.

I'm running a ~425hp 5.3 (LH6 with flat top pistons, ~10.2:1 compression, 799 heads, TBSS intake) with a TSP Bald Eagle N/A cam, T56 Magnum with a Vengeance Clutch dual disc, 4" custom driveshaft and the original 10-bolt built as stated above with 3.90 gears and a Yukon Duragrip posi unit. Got 41k on everything but the trans swap, almost 15k on the T56 setup. Regular drop spindles, cut springs up front, flip kit and a shackle in the back for a ~5/8 drop. The only thing I don't like about my setup is I need more gear (going 4.30) and it wheel hops real bad so it needs traction bars (but I have TCI full pro-touring suspension to go on it). Otherwise it's a riot

TotalyHucked said:

I did the LS thing a few years ago and it's by far the best thing you can do to these trucks. Here's what sticks out to me:

- A) Pick a better cam. That cam sucks in a heavy truck. My buddy's got it in a suburban and my god is it a dog.
- B) The 706 heads are a good choice to bump compression. They won't hurt flow (unless you're turning it 7500+ and then any OE head is going to be limited)
- C) The only way to know for sure if your cam will work with the heads/not have PTV issues is to check PTV yourself. You can also talk to Texas Speed and they can give you a rough yay or nay but the only way to know for sure is to check it yourself
- D) That AR-5 isn't going to last long if you plan to beat on it. Drive it nice and hopefully never hook up, with a good clutch and you'll be ok. I have a Vengeance Clutch dual disc in mine with a T56 and it's awesome
- E) Stock truck manifolds don't clear the frame. Get headers or the Hooker manifolds
- F) You should already be drive by wire being an '06 engine. The TBSS intake is a good power bump on any LS
- G) You lost me on the computer side. I used the donor Envoy E40 computer that came with my engine and my buddy/tuner tuned it with HP.


For the suspension, you're going down a rabbit hole nobody else has been. Also, there are literal thousands of 5x5 wheels, there's no benefit whatsoever to go to 6-lug. Most 6-lug guys with the older trucks convert to 5-lug. Also, that 2000 Silverado rear end won't have the correct mounting pads or anything to mate up to your leafs most likely. Not to mention it'll have the GM "Gov-Loc" that is not at all desirable (it's called a Gov-bomb for a reason) and a terrible rear disc design that never works well. I would highly suggest just using your original 10-bolt and building it up (I did mine with 30-spline stuff from Quick Performance that should be good through 6-700hp) or pick up a 9-inch from QP that's set up for these trucks.

I'm running a ~425hp 5.3 (LH6 with flat top pistons, ~10.2:1 compression, 799 heads, TBSS intake) with a TSP Bald Eagle N/A cam, T56 Magnum with a Vengeance Clutch dual disc, 4" custom driveshaft and the original 10-bolt built as stated above with 3.90 gears and a Yukon Duragrip posi unit. Got 41k on everything but the trans swap, almost 15k on the T56 setup. Regular drop spindles, cut springs up front, flip kit and a shackle in the back for a ~5/8 drop. The only thing I don't like about my setup is I need more gear (going 4.30) and it wheel hops real bad so it needs traction bars (but I have TCI full pro-touring suspension to go on it). Otherwise it's a riot

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on the ECU thing just so you understand a little better, the P01 blue/red ECU's where all drive by cable throttle and do not have the hardware in the ECU to control a drive by wire throttle setup. the P59 blue/green connector ECU's are for drive by wire setup's for the most part and are missing the ECU hardware to control the idle air controller on a drive by cable setup. On the P59 there is 1 odd ball ECU that has the hardware to control the drive by cable idle air solenoid and thats the one that comes from a 2003 4.3L blazer as all blazers are drive by cable but in 2003 they got the upgrade from P01 to P59 ECU just like the V8's did.

lastly P59 ECU's do have a spot on the board to control to control the early idle air solenoid. you can rob said parts from a P01 and solder them into your P59 to make the one that the door swings both ways. getting the P59 blazer ECU is just an easier way to get the universal ECU without having to cannibalize a P01.

SquareRoot said:

Thumbs down for mating a 6.0 to a Colorado transmission unless there's something I don't know about.
Thumbs up for spelling axle correct.
We're gonna need pictures of this Frankenstein.

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the guys at sloppy mechanics proved the AR-5 is a pretty durable tranny. they put 900hp and 800ft/lbs of torque through one for a long time before it failed. correct me if im wrong but even a stock T56 cant handle that. im not scared of breaking the AR-5 either because they are cheap. i got a 4WD one for 300 bucks and the place i got it has a pile more at the same price. fabbot has the stuff to convert the 4WD AR-5 to 2WD so i bought that stuff too. im PA so 2WD vehicles are not as plentiful as they are down south to get a true 2WD AR-5 easily.

not really much to see right now with the truck. its literally in a pile of itself covered in dust from sitting in the garage for the past 8 years. story behind it is that have always liked square body trucks ever since i rode in the ones on my familys farm when i was a kid. my little brother contacted me like 8-9 years ago and told me his friend had a square body for sale. normally i would have ignored it because every time someone wanted to sell one its it was a long bed or a step side. never a short bed fleet side like i wanted. it was my little brother so i entertained the truck. it was exactly what i wanted, short bed fleet side! it was inline 6 with turbo 350 trans that was dead and not a speck of rust to be seen anywhere so i bought it. plan was to give it to my little brother after i did all of this to it because he has always been down on his luck and needed something to help raise him back up. well lack money and life got in the way of the truck so it sat in a corner for all those years than sadly my little brother passed away in 2022 so the truck is now going to be a tribute to him that i will keep as long as im alive and will eventually be willed to his daughter when im gone.

vwnut8392 said:

not really much to see right now with the truck. its literally in a pile of itself covered in dust from sitting in the garage for the past 8 years.

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pics are always nice.....regardless of condition. Think of it as a documentary for yourself (and wife if she b|tches about progress too much lol).

Camar068 said:

pics are always nice.....regardless of condition. Think of it as a documentary for yourself (and wife if she b|tches about progress too much lol).

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well thats when i first picked it up 8 years ago. inline 6 automatic truck, pretty much base model work truck. absolutely hate the 81 grill and plan to change that. i got all the parts to convert the truck to manual as if it was that way from the factory from a friend who was stripping like 77 dump truck for parts. it has the proper steering column for a manual that i rebuilt. OEM original pedal box and pedals for a manual that i modified the clutch pedal to be used with a hydraulic master from an 87 C10. i located the proper spot in the firewall on a truck in the junkyard to install the master in the OEM correct location.

im a german car guy hence the user name so i plan to use some stuff from the german car world. one thing i plan on putting in the truck is these blue recaro seats that came out of a limited edition VW jetta in 1989. also got a center console from a K15 blazer that im going to try to retrofit in between the seats.

These are the recaro seats that i will be putting in it look like.

Part of my inspiration is roadkill's muscle truck. yes i want to swap the front end to a 70's front end. if my truck runs anything like freiburger's truck does i'll be happy with it. i know his truck had an LS6 in it but thats a 5.7, mines bigger hence 6.0L power lol.

vwnut8392 said:

These are the recaro seats that i will be putting in it look like.

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Awesome! Pics always create idea's for others.

vwnut8392 said:

the P01 blue/red ECU's where all drive by cable throttle and do not have the hardware in the ECU to control a drive by wire throttle

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I’ve got a 2000 Tahoe 5.3/4L60 that is factory drive by wire. DBW was included in the RPO NW7 Traction Control system.

I have the Jegs 460hp 5.3L crate engine, built 4L60, 3:73 posi rearend, and a 3400 stall Circle D converter. The truck gets 16mpg if I keep my foot out of it, but I love standing on the loud pedal!!!

TotalyHucked said:

- A) Pick a better cam. That cam sucks in a heavy truck.

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So true!!

well here's an update, it runs and moves!! i semi rigged an aluminum driveshaft from a 2000 silverado for now so i can at least move it around on the property at my shop till i can afford to get one custom made for it. i think it needs a tune up too but its hard to tell with the chop monster cam lol. either way im going to toss a set of wires and some fresh plugs in it. i bought the EFI tank and leveler as you guys suggested for it plus i tossed in a genuine mopar hellcat 525lph pump so if i decide to turbo it later i dont have to change the pump. buddy works at a dodge dealership, flagged a hellcat no run for a bad pump hahaha! yes im still running stock manifolds that i modified with 2in V-bands but directly after the V-bands it steps up to 3in stainless pipe and currently ends right at the cab because thats all i had enough pipe for. plan is to build an X pipe and dump the exhaust out of the sides before the front tires with modified OEM 98-02 trans am aluminum exhaust tips for something different. im going to mod them to be 3in with a 3in aluminum V-band on one end and a matching steel V-band on the other end to attach them to the exhaust.

beyond that stuff its been tedious work with wiring up the P59 ECU to the truck. i added a whole separate fuse box that powers all of that including a starter relay, fuel pump relay thats controlled by the ECU, both fan control outputs from the ECU also run relays for the fans. i need to get the 3 pin coolant sensor so i can get my stock coolant gauge working along with an oil pressure sender for the stock dash as well. im probably going to just rig up an old cell phone with the torque app over bluetooth in HUD mode so i can have a tach and a speedometer since buying an aftermarket gauge cluster isnt in the budget right now. next step when money prevails is to get the drive shaft made, get a lowering kit for 5-6 drop and im definitely getting 5x127 to 5x120 adapters because i was given a set of late S10 ZQ8 wheels by a friend of mine plus any good looking GM factory wheel seems to have been or is 5x120 bolt pattern. drop a set of ZR1 vette wheels on it if i ever come across a set.

forgot to mention that i will be doing all the tuning on it myself. basically im running a P01 red/blue harness that i modified, it is DBC as well because that just made the swap easier. im also running a P59 red/green ECU as well because of its extended functionality over a P01 ECU. this P59 ECU is from a 2003 GMC sonoma 4.3 V6 truck because those where one of a very few P59's that had the ability to run both DBC and DBW.

Since this truck was originally destined to be my little brothers truck who passed away in 2022 its now going to be a tribute truck to him that i will keep forever and when i die it will go to his only daughter.

Colorado 5 speed worked out pretty good in it too! cue ball shift knob is a special thing for me because it was in my friends dads dodge work truck since 1982 which at one point was my work truck when i worked for their company. i grew up with him and sadly he passed away several months ago as well and the old dodge has seen better days so i grabbed that cue ball off the shifter before it went to the scrap yard and put it in my truck in memory of him.