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#1 |
Registered User
Join Date: Oct 2008
Location: Brighton, TN
Posts: 1,267
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6.2L or 8.1L
My 86 Crew Cab C30 has a tired old 454 and im going to be replacing it in the next couple months. Ive really been looking into using an 8.1 cause it bolts in place of the 454 thats in it and saves me from having to buy a new transmission as well as several other things that have to be modded for the LS platform. But at the same time if I can snag a 4l80/5 I can put my gear vendors overdrive unit on it and have underdrive as well. However the 6.2L has its perks as about the same HP not as much torque but easily upgraded and lots of aftermarket parts for support. So I guess while im pondering Ill put it out to you guys to see what you think. I will be pulling a 30+ foot camper and maybe at times a GN or 5th wheel car trailer. Just a little more info.
Pic of the dually for reference.
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A computer once beat me at chess, but it was no match for me at kick boxing. Duct tape is like the force. It has a light side, a dark side, and it holds the world together. |
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#2 |
Registered User
Join Date: Oct 2014
Location: Spearfish South Dakota
Posts: 407
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Re: 6.2L or 8.1L
Had an 02 with a 8.1 loved power but was hard on gas. Had a new 02 work truck same time it had 6.0 . It had decent power and better mileage not sure what 6.2 is old diesel? Oh ya nice truck.
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83 c10 long Box Daily Driver 90 Jimmy parked 98 Road King/ 06 Road Glide In memorium 63 impala SS/ 65 Chevy Panel 65 GMC Short Box/ 68 Camero |
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#3 |
Registered User
Join Date: Oct 2008
Location: Brighton, TN
Posts: 1,267
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Re: 6.2L or 8.1L
6.2 is the latest LS engine came in the escalades and the denali's. I had an escalade with one and it did good for towing my 18ft trailer with a truck on it. This truck is a bit heavier and ill be pulling bigger loads. I guess the question is how good of gas mileage do i really expect out of either setup pulling a huge 30ft camper?
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A computer once beat me at chess, but it was no match for me at kick boxing. Duct tape is like the force. It has a light side, a dark side, and it holds the world together. |
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#4 |
Registered User
Join Date: Oct 2014
Location: Spearfish South Dakota
Posts: 407
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Re: 6.2L or 8.1L
Wow punch 6.2 in lot talk. Looked at a crate Eng. 8 grand have to run premium gas I would probably just rebuild the 454. have 5 grand left over for gas.
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83 c10 long Box Daily Driver 90 Jimmy parked 98 Road King/ 06 Road Glide In memorium 63 impala SS/ 65 Chevy Panel 65 GMC Short Box/ 68 Camero |
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#5 |
Registered User
Join Date: Oct 2008
Location: Brighton, TN
Posts: 1,267
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Re: 6.2L or 8.1L
True but some of that would be eaten up by the fact im ditching the carb and going fuel infected. Tired of dinking with carb setups.
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A computer once beat me at chess, but it was no match for me at kick boxing. Duct tape is like the force. It has a light side, a dark side, and it holds the world together. |
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#6 |
Registered User
Join Date: Jul 2012
Location: MA
Posts: 207
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Re: 6.2L or 8.1L
My 2012 is peppy with or without a load in the back. Hook a trailer to it, and it has me wanting a little more grunt. I typically tow 6000-7000 lbs a few times per year, for a few hundred miles at a time. Total combined weight about 15K. Kind of wish I got the Duramax. but I don't tow that often, and it is perfectly adequate when I do.
This is assuming the 6.0 and the 6.2L engines perform similarly. If I were building a truck to tow, I'd go 8.1L or Cummins. I'd want the Allison to go with it though. The 4L80E didn't come with the 8.1, unless it was in the van I think. One word of warning, and this is second hand info at best; but the 8.1L motors seemed to have some oil burning issues. Seems like some guys on other message boards had to rebuild their engines because of excessive oil consumption and piston slap/scuffing. I have not hand any first hand experience with these motors so that could just be rumor or bashing. What about rebuilding the 454 and adding aftermarket (like Holley) FI? Not really original, but it will give you a strong truck with dependable power for a reasonable-ish price.
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2012 Chevy 2500HD, 6.0L, 6spd auto, 4x4, ECSB 1987 GMC V3500 Dump, 6.2L diesel, TH400 1983 GMC K2500 - awaiting its restoration and Cummins swap. Last edited by crashz; 04-15-2015 at 04:13 PM. |
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#7 | |
Registered User
Join Date: Oct 2008
Location: Brighton, TN
Posts: 1,267
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Re: 6.2L or 8.1L
Quote:
That being said the 8.1 with just a tune on the computer and some added fuel pressure are putting out 450hp and 630ish torque at like 3500 rpm's which ought to pull a darn tank. I will be pulling the camper 100 miles or so every couple a weekends during the summer and taking the truck to shows as well. So gas mileage is not something i really expect. I just want to make sure the power is there when i need it.
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A computer once beat me at chess, but it was no match for me at kick boxing. Duct tape is like the force. It has a light side, a dark side, and it holds the world together. |
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#8 |
Registered User
Join Date: Jul 2012
Location: MA
Posts: 207
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Re: 6.2L or 8.1L
Yeah - I think my 6.0 has 360 Hp in stock form. Can't remember torque. So the 6.2L would have the power advantage.
I get about 14 mpgs when the stars are aligned, empty truck, easy & flat highway driving and no faster than 65 mph. Towing is as low as 8 mpgs. My truck weighs in at a portly 7500 lbs empty. I have 265/70 R18 tires and 3.73 gears (thought that would help with mileage!!) with the 6L90E auto transmission. My guess is that either engine will be hovering around the 10 mpg range no matter what. Might as well go for all the grunt you can get.
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2012 Chevy 2500HD, 6.0L, 6spd auto, 4x4, ECSB 1987 GMC V3500 Dump, 6.2L diesel, TH400 1983 GMC K2500 - awaiting its restoration and Cummins swap. |
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#9 | |
Registered User
Join Date: Oct 2014
Location: Spearfish South Dakota
Posts: 407
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Re: 6.2L or 8.1L
Quote:
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83 c10 long Box Daily Driver 90 Jimmy parked 98 Road King/ 06 Road Glide In memorium 63 impala SS/ 65 Chevy Panel 65 GMC Short Box/ 68 Camero |
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#10 |
Windy Corner of a Dirty Street
Join Date: Jun 2003
Location: Pueblo West, Colorado
Posts: 2,926
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Re: 6.2L or 8.1L
Dunno why anybody would want an 8.1L
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Current vehicle collection: 1978 Chevrolet K10, 8.1L, NV4500, NP205 1989 Chevrolet Suburban, 8.1L, NV4500, NP241 1993 Chevrolet C1500 Sportside, TBI 7.4L, 4L60E 2001 Chevrolet K2500HD, Ext Cab, SWB, 8.1L, ZF 6 speed 2014 Chevrolet Impala LTZ 3.6L Vortec 8.1L because life is too short to tolerate underpowered vehicles
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#11 |
Registered User
Join Date: Jan 2009
Location: Southern Md
Posts: 228
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Re: 6.2L or 8.1L
I am jealous, that is a nice looking truck. Cant find one for my self to save my ___.
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04 Yukon XL 2500 w/ Quadrasteer ![]() 61 Chevy C60, 261 inline six 86 Chevy C20 2wd, Banks 6.2 05 GMC Sierra 2500hd Duramax |
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#12 |
Registered User
Join Date: Oct 2008
Location: Brighton, TN
Posts: 1,267
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Re: 6.2L or 8.1L
It's your fault I'm even considering this larry!! Lol. I am pretty much convinced to go 8.1 but figured I would consider the 6.2 since they are more plentiful and have a better aftermarket following. But their torque just isn't as much as the 8.1.
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A computer once beat me at chess, but it was no match for me at kick boxing. Duct tape is like the force. It has a light side, a dark side, and it holds the world together. |
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#13 | |
Windy Corner of a Dirty Street
Join Date: Jun 2003
Location: Pueblo West, Colorado
Posts: 2,926
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Re: 6.2L or 8.1L
Quote:
![]() The best ,and worst thing, about the 8.1L is nobody knows a damn thing about them.
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Current vehicle collection: 1978 Chevrolet K10, 8.1L, NV4500, NP205 1989 Chevrolet Suburban, 8.1L, NV4500, NP241 1993 Chevrolet C1500 Sportside, TBI 7.4L, 4L60E 2001 Chevrolet K2500HD, Ext Cab, SWB, 8.1L, ZF 6 speed 2014 Chevrolet Impala LTZ 3.6L Vortec 8.1L because life is too short to tolerate underpowered vehicles
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#14 |
Registered User
Join Date: Dec 2013
Location: Columbus, Oh
Posts: 366
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Re: 6.2L or 8.1L
My vote would be for the 8.1L.
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#15 |
Registered User
Join Date: Jul 2012
Location: Des Moines IA
Posts: 1,250
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Re: 6.2L or 8.1L
For a crew dually I would go 8.1 as well. Nothing like 400 foot pounds barely off idle for towing.
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- 1981 Sierra 454, NV4500 swap - 2006 Z06, 25k miles - 1973 Nova - Project CarNova Virus on Youtube |
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#16 | |
Moderator
![]() Join Date: Oct 2008
Location: Wentworth, NH
Posts: 4,951
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Re: 6.2L or 8.1L
Quote:
I've seen a handful of 472 & 500 CID caddy engines in these trucks for that same reason. 496CID with modern fuel injection... If I had the 76 to do over I'd go with an 8.1
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1959 M35A2 LDT465-1D SOLD 1967 Dodge W200 B383, NP420/NP201 SOLD 1969 Dodge Polara 500 B383, A833 SOLD 1972 Ford F250 FE390, NP435/NP205 SOLD 1976 Chevy K20, 6.5L, NV4500/NP208 SOLD 1986 M1008 CUCV SOLD 2000 GMC C2500, TD6.5L, NV4500 2005 Chevy Silverado LS 2500HD 6.0L 4L80E/NP263 2009 Impala SS LS4 V8 RTFM... GM Parts Books, GM Schematics, GM service manuals, and GM training materials...
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#17 |
Registered User
Join Date: Oct 2008
Location: Brighton, TN
Posts: 1,267
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Re: 6.2L or 8.1L
I have pretty much talked myself into the 8.1 but I did that along time ago. lol I was considering the 6.2 as another option if I cant find a suitable 8.1. I think I have found one though that's still on a burb 2500 chassis. motor trans and everything with very low mileage. now I just have to get my cash together. its got the 4l80 behind it I think that's whats in a burb and if that's the case im gonna add my GV overdrive onto it from my 400 I have now. Probably wont be good for towing other than the underdrive but on just a flat run ought to help with gas mileage a bit.
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A computer once beat me at chess, but it was no match for me at kick boxing. Duct tape is like the force. It has a light side, a dark side, and it holds the world together. |
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