6.2 LS3 vs. 8.1 decision

Blackwater

Original poster
Member
Aug 14, 2015
477
Lawton, OK
Im planning my next stage in my truck build. If you have read my profile and seen my pictures you will seen I have done a lot already. My original plain was a 408 stroker out of a LQ9 block. I found out the stroker is not a good DD. so I looked at having a 6.2 LS3 from jegs with krooks tuned headers and a 92mm intake. or go cheap and get a used 8.1. Im looking for some power with some gas saving bennies. Any thoughts?
 

Sparky

Member
Dec 4, 2011
12,927
I would think the 6.2 would give you plenty of power but be better on fuel than a big block.

Huge aftermarket for the small block LS based engines also.
 

HARDTRAILZ

Moderator
Nov 18, 2011
49,665
8.1 sucks fuel
 

Blackwater

Original poster
Member
Aug 14, 2015
477
Lawton, OK
I was thinking that 8.1 is a little much but would add more uniqueness to the ride. but so would the 6.2L. I was also thinking of changing the diff gears from 3.73 to 3.42 since I never use 1st. I dont think that changing the diff gears wont effect my torque much since I have such a low 1st. right now I can pull stumps out of the ground as is.
 

Paul Bell

Member
Aug 16, 2014
460
How in the world would you get a big block to fit? Oil pan and exhaust comes to mind first then a whole laundry list of other things.
 

HARDTRAILZ

Moderator
Nov 18, 2011
49,665
93 full size...
 

Blackwater

Original poster
Member
Aug 14, 2015
477
Lawton, OK
Yes, its a full size HARDTRAILZ. I play with Tonka, not Matchbox :tongue: . I have thought about getting a compact truck for going to and from work. But I am a large guy. It would be like stuffing a whole tuna in one tin. But I have seen blown 454 CID in a S10, Paul Bell. Prescott speedway in Prescott, Arkansas. I was a teenager then. They also had a blown commaro and mustang.

I know that a 8.1L is nothing more then a mild stroked 7.4L from the factory. Designed with low end torque. There is a guy in CA that has aluminum heads, three different cams, and custom headers for the beast. I also noting there is a chevy 705CID online. Coffee cans for pistons I bet.

I think I will go with the 6.2L/480hp 475ftlbs torque crate from Jeggs. then add the kooks tuned headers and a 92mm TB. Hopeing to push it just over 500hp and 490ftlbs of torque. Run it to a speed shop in OKC for a dyno tune it and call it a day. Then work on body and interior.

As for the rear diff, I am still not sure on changing the 3.73 to a 3.42. I will have 1/3 more torque from the 6.2L and possibly start using 1st again. I get 19 mpg on the freeway as of now with the stock 350 TBI with 300ftlbs from the fly.
 

Paul Bell

Member
Aug 16, 2014
460
HARDTRAILZ said:
93 full size...
AHH I see. Sorry, missed that. :redface:

Yes, all fullsized trucks SHOULD have a big block engine in it.
 

Blackwater

Original poster
Member
Aug 14, 2015
477
Lawton, OK
For now I need to iron out what I have accomplished already. Recently, I had bad vibrations from the truck since I did the mods. From experience, you always go back to where you shit last and work your way back. I call out the drive shaft causing the vibrations in the truck. Before I jumped in and went with the drive shaft. I had a free check on the balance of the tires and the most anyone of those where off was 1 oz. so I removed the drive shaft and had it looked at for balance in Oklahoma City, OK (OKC) with the guys at Precision Drive LTD. These are the same guys who does the drive shafts for the guys who are on Street Outlaws. It came back and please note this was a new drive shaft, with a missing "C" clip in the front U-joint. It wasn't straight so then we new immediately it wasn't balanced properly. Replaced the rear seal on the gearvendors. checked the pinion seal. pinion was good. yoke loose. This maybe due to the vibrations. Im keeping all of these maintenance issues, parts, torque specs, and mods in a engineering book. I plan on heading back to El Paso to chew some *** on the original builders of the drive shaft.
 

Blackwater

Original poster
Member
Aug 14, 2015
477
Lawton, OK
Factory 350 TBI miznitic.
 

Blackwater

Original poster
Member
Aug 14, 2015
477
Lawton, OK
I think I'm going back to my original idea and Go with the LS3/480hp. A co-worker is trying to convenience me to keep the 350 TBI and mod it. I like the LS style. He claims that I need low end torque and not high end and a heavy starting torque. Why not both? My peek torque is 300lb-ft @2800 rpms. the starting torque to the LS3 480HP starts at 300lbs-ft @ 800rpms. The LS3/525 starts at 328lbs-ft @ 800rpms. I think its a good start and has high horsepower at the top end and 475 lb-ft @4500 rpm 480 hp @ 5700 rpm. I don't know...I think that is a good starting torque. I think he is scared that my old truck will smoke his mustang. I know if we have a tug-o-war and I drop it in first that I can pull him backwards. any thoughts? Keep the old or grab the new?
 

HARDTRAILZ

Moderator
Nov 18, 2011
49,665
Go new and whoop his stang ass
 

Blackwater

Original poster
Member
Aug 14, 2015
477
Lawton, OK
I already keep up with a 2014 camaro ZL1 on the streets. Dont know how I will far on 1/4 mile with one. Most of the guys are already impressed with the current mods.
 

littleblazer

Member
Jul 6, 2014
9,265
So it currently has the 350? If so doing the 6.2 you will notice a slight drop in oomph off the line... but low mid range it'll just pull.
Pros of 350: There are thousands of them and mods are cheap
Cons: Lot easier to get more power from an ls.
Pros of both: Damn reliable, you really can't make a wrong choice here. :biggrin:
 

RedRocketZ28

Member
May 16, 2014
114
I already keep up with a 2014 camaro ZL1 on the streets. Dont know how I will far on 1/4 mile with one. Most of the guys are already impressed with the current mods.

Define what keeping up on the streets means. As in you can still see the car as it pulls away effortlessly, or you actually hang in with one from a dig, roll, etc.?

No way your full size truck with a 350 TBI comes anywhere close to a ZL1 Camaro. They are low 12 second cars completely stock...
 
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Blackwater

Original poster
Member
Aug 14, 2015
477
Lawton, OK
I'm really wanting just to modernize the truck and just get that wow factor. I know if I ever decide to sell it, it would be to a collector otherwise I would not get nothing for what I put in it. It so far is a one of a kind truck. Very unique. I get complements all the time. even a $4000 offer. I declined. at that time I just dumped $7000 in it.
 

Blackwater

Original poster
Member
Aug 14, 2015
477
Lawton, OK
red rocket. we were racing from one point to another on the same route.
 

Blackwater

Original poster
Member
Aug 14, 2015
477
Lawton, OK
All my mods are from the back of the engine to the rear wheels
 

Blackwater

Original poster
Member
Aug 14, 2015
477
Lawton, OK
When we got back to the company parking lot and asked me whats in it. I showed him and he commented "F***ing sleeper. Now you need a power plant to turn what you have in-front of your mods and your gold."
 

RedRocketZ28

Member
May 16, 2014
114
I would be interested to hear what you have done.

There isn't anything you can do to that trucks stock drivetrain to make it run with a ZL1 Camaro.

To get back on track with your thread though, I would LS swap it for sure. Will be a night and day difference from that motor you have in there.
 
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Blackwater

Original poster
Member
Aug 14, 2015
477
Lawton, OK
Red there is plenty you can do as long as you have room under there and there is time and money.
 

HARDTRAILZ

Moderator
Nov 18, 2011
49,665
Can you share what you have done?
 

Blackwater

Original poster
Member
Aug 14, 2015
477
Lawton, OK
I found a transmission from a junk yard to replace the NV3500 I had in the truck. I was tired of them going out and I planned on add more power to the truck. Yes I can do burnouts in its stock factory condition. I wanted more. The transmission came out of a 2004 3500. The NV4500 RPO: MW3 was what I was looking for. but then the 8.5" 3.08:1 rear diff would be the weak link. so I found a 9.5" 373:1 semi float rear end from a 1992 K2500LD. I rebuilt the rear diff and added a Detroit locker to it. Had the tranny rebuilt by Bob from Southwest Gear in El Paso Texas. Good shop to go to for manuals and diffs. he does autos as well. Then ordered a Gearvendors from Gearvendors.com. I did some modding on the gearvendors install, since it was for a 3/4 and not a 1/2 ton. Got it in. I had a choice to spend the money on converting the tail shaft of the tranny to a slip or get a second tranny with the slip option. Had a drive shaft made by U-joints Inc in El Paso. The new guy built this one and messed up but didn't have time for them to fix it due to me moving the next day. If you go there request Carlos to build it. He is good in that shop. I latter had it straightened and re-balanced at a place in Oklahoma city. Little did I know until walking in that this shop is the preferred shop of the Street outlaws. I also realized I had a problem with the clutch. It was pre-loading. My 1993 clutch works with both NV3500 and NV4500 of the years 93 thru 97. I did some research and found that a 1998 3500 clutch will work. That was interesting since the whole time had no advise for the whole conversion. I think I have settled on the LS3 480hp to replace the trucks factory 350.

I also have to convert my front from 5 lug to 6. That was easy since the 2500LD shared spendales, brakes and bearings. But now im 4' narrow in the front. I have a fix for that as well and its not spacers. I used 17" aluminum rims from a 2007 Yukon. with 245/70/R17 bridgestone dueler A/T's.
 
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HARDTRAILZ

Moderator
Nov 18, 2011
49,665
I guess he is a shitty driver cause you did nothing to make a 210 HP truck faster, stronger yes, but not faster and a ZL1 is flat out fast. Even the 93 454SS truck was considerably slower.

2013 Chevrolet Camaro ZL1 0-60 -- 4.0 | Quarter mile 12.3
1993 Chevrolet 454 SSC 0-60 -- 7.1 | Quarter mile 15.6
 

Blackwater

Original poster
Member
Aug 14, 2015
477
Lawton, OK
Consider this, with my set up I have 10 gear combos. each gear is about 500rpms apart from each other which would allow me to stay in the power band and stay out of the basement. engine stays maxed out all the time. I just switch gears more. I posted pictures of my truck on my profile but dont know where they went and dont know how to post them in a thread yet.

I did a 14.56 in a 1/4 in 2002 with the stock version. Everyone noticed a big difference in the truck when they rode in it after the mod.

And now I probably been put on the do not believe list.
 
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HARDTRAILZ

Moderator
Nov 18, 2011
49,665
Please stop double posting...

How did you beat a 454 time stock? It is pretty tough to believe.

I do see how the over/under would help keep the power useful and should really be something with double the ponies. Get the motor in and get us some timeslips. Should be badass then!
 

Blackwater

Original poster
Member
Aug 14, 2015
477
Lawton, OK
double posting?
 

Blckshdw

Moderator
Nov 20, 2011
10,665
Tampa Bay Area, FL
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Blackwater

Original poster
Member
Aug 14, 2015
477
Lawton, OK
Ah, wasn't aware of this. Thanks for the heads up.
 
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Blackwater

Original poster
Member
Aug 14, 2015
477
Lawton, OK
Ok, I have thoroughly read it and think that now I am close to being banned and put on the do not believe list. How do you post pictures on here to show what I was talking about. Where did the picture go in my profile?
 

HARDTRAILZ

Moderator
Nov 18, 2011
49,665
Not sure why you think you would be banned.

The do not believe is just due to claims that seem unbelievable and are unsubstantiated. A truck w 1/3 of the HP beating one of the fastest new cars out seems it would have to be a shitty driver honestly. I have driven and ridden in several new Camaros and owned several older ones as well owned and driven many stock and modded GM pickups. They are in two different classes of quick. And then your stock truck beats the stock 1/4 mile time without mods when it is near 10 years old makes no sense. Especially when the you claim over a second faster than the fastest of the production GM pickups that year. But may be it is true.

Pics are easiest to load to photobucket and post for me. That is how I do all of mine. Simple and effective.
 

Blackwater

Original poster
Member
Aug 14, 2015
477
Lawton, OK
I understand that. wish I kept the ticket but that was years ago. It was a free for all down a Prescott speedway in Prescott AR. But the speed may have been the set up and/or driver. been driving on the farm since 7. dads 86 GMC dully. maybe the tracks timer needs calibrations.
 

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HARDTRAILZ

Moderator
Nov 18, 2011
49,665
I run a 9.5 on my Trailblazer, what cover is that? Looks good.

The under/over are sweet but I could never justify the cost of one.
 

Blackwater

Original poster
Member
Aug 14, 2015
477
Lawton, OK
G2 cover. It features are a 1.5 quart increase, drain, dipstick with magnets. as far as the gear vendors, I have a short bed regular cab truck and I would need a two piece drive shaft to get it to work otherwise. I love my gearvendors. I went from 16 mpg to 19 and helped me move my family. After trying to go the posted speed limit of 80mph but slowed down cause of trailer sway. I decided to stop and weigh it. without driver and passenger it was just under 14000 lbs. the NV4500 helps a lot as well. But im dead set on the LS3 6.2 480 hp from GM performance. oops forgot to post pictures. have to wait. here is where I got the diff cover. http://www.summitracing.com/parts/gta-40-2023mb/overview/
here is the locker I used but if I have to do it again I would use a e-locker.
http://www.summitracing.com/parts/DTL-225C135A
 
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HARDTRAILZ

Moderator
Nov 18, 2011
49,665
Post pics of what?

Ahh...I think that is one of the covers too thick to use with the panhard.

Why a two piece shaft w the gearvendors? I have had several driveshafts built over the years n think only front ones have been two piece.

Nice MPG bump for sure.

Fairly heavy load for a short bed. Not surprised you had sway. Were you running a weight distribution hitch?
 

Blackwater

Original poster
Member
Aug 14, 2015
477
Lawton, OK
here are more pictures.

It was either a two piece drive shaft or the gearvendors cause the NV4500 4x2 came with a fixed yoke.
in the first two pictures shows the distributing hitch but I balanced out the weight in the trailer so well It only brought it up 3 inches in the back.
 

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HARDTRAILZ

Moderator
Nov 18, 2011
49,665
Right on. Makes it easier to justify the GV unit. Little over weight on the trailer, but I know plenty that tow far worse. I like the wheels on the truck
 

Blackwater

Original poster
Member
Aug 14, 2015
477
Lawton, OK
thank you. Junk yard for $350. Since I am temporarily off the field engineering trail I started engineering the truck. Is that a CB I see on your rig? I have two 102in whips behind my cab.
 

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