Help- which truck indecision! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

D13 · 03-23-2007, 06:04 AM

in the market for a driver, 70+ Michigan miles a day 5 days a week, 3 miles dirt 20 miles highway 10 miles city rest country. Really like 81-87 GMC and Chevy full size. looking for reasonable fuel mileage and long life, and not a 4wd. Already hav a 99 NBS tow beast so that's not really an issue. Found several possibilities and would like input.

84 1/2 ton 250 6cyl THM350 100k probably 3.08 or 3.23 10 bolt so could put 2.73 in it. Beleive this would get 17mpg or so as sitting, would look at swapping in 2004R and getting close to 20mpg. $3k + trans
84 1/2 ton 6.2 diesel auto 100k would this get 18mpg? $5k Anyone know what trans and rear end and ratio it is likely to have?
87 3/4 ton 5.0 probably a 700R4 60k I would bet 15-16 mpg probably 3.43 14-bolt so not much more highway gear available $5k

All have decent to great bodies and interiors. I'm assuming that the tires etc are in eqivalent shape and that I have to add a posi to whatever I get. I'm very familiar with the 6cyl, SBC are common and I know nothing about diesels.

All opinions welcome!

Blackstone · 03-23-2007, 07:01 AM

I think the six-banger is called for in this situation. Considering the extra cost of diesel fuel, there isn't much to gain there.

rcbildr · 03-23-2007, 07:35 AM

I think the diesel should get better than 18mpg, my 2wd diesel burb got at least 22mpg. My 4x4 diesel burb gets 19mpg. My guess is the truck has a 700R4. Not sure about the rear gears, of the 3 diesel rigs I have in my yard the 2 Suburbans have 4.10's and the 83 4x4 shortbed has 3.73.

grinch4om · 03-23-2007, 07:45 AM

my vote for the six

**old Rusty C10** · 03-23-2007, 09:23 AM

id vote for the six myself a company i worked for had two FOrd vans the exact same E250 trucks one being diesel and one being the v8 gas and they got the same exact mileage

Slonaker · 03-23-2007, 09:34 AM

Since MPG seems to be an issue, I would buy the diesel or wait until you can find an '87. They are fuel injected, and have overdrive transmissions available.

Slonaker

D13 · 03-23-2007, 01:27 PM

The 87 is FI but 5.0. I need to find out if the 84 6.2 has O/D. They did not offer L6 with FI in the US, went 4.3 instead, would happily buy one except everyone seems to have replaced them with carb 5.7.

rcbildr · 03-24-2007, 02:41 AM

Quote:

Originally Posted by D13

The 87 is FI but 5.0. I need to find out if the 84 6.2 has O/D. They did not offer L6 with FI in the US, went 4.3 instead, would happily buy one except everyone seems to have replaced them with carb 5.7.

Neither of the 2 diesels I have driven had O/D...the 2wd had a TH-400 and I converted my 4x4 to an SM-465. The shorty actually belongs to a good friend of mine, and shortly after I got it running (had to replace the engine) the tranny (700R4) went out on it.

74 shortbed 406 · 03-24-2007, 11:37 AM

In my experience the six will drink just as much as a 350. I had a 74 with 350 turbo and 3.73 rear gears. The six got 10-13 depending on how hard you pushed it and the 350(stock rebuild) got 13-14 and it was more consistent on mileage. As for the 87, I have one now with tbi 350, 4x4, 465 tranny, and 3.08 gears and it is at 14-15.

dswancutt · 03-24-2007, 11:59 AM

The 250 sixes with intergral heads also have tendency to crack heads. That is what happened to my 79 with a six. I never got really good gas mileage with it, but the motor was shot. I would go with the 87 5.0. I have a 78 k-10 with a 5.0 running 3.73 gears and could get 13 mpg, and that was with a wore out carb.

Pyrotechnic · 03-24-2007, 02:19 PM

A 305 with 2.73's and a Turbo 350, or a 305 with 3.08's and a 700R4 are good combos for getting really great gas mileage. Possibly into the 20MPG range. The 700R4 will be the best bet since it's got a lower first gear to make take off easier, and it's got the lockup clutch which will help out a lot too. I would go for the 305.

Hoods69BadBowTie · 03-24-2007, 02:57 PM

I vote for the 5.0 motored truck.

Duro5341 · 03-25-2007, 11:31 PM

Personally I would go with the diesel, being your concerned about MPG, and long lasting.....you won't beat a diesel in these catagories

I would guess the diesel would have a TH400, and a 14 bolt rear end....with the massive amount of torque the diesel will put out...these would hold it quite well.

Also the diesel will be better if you ever decide to pull anything....you will have no problems

Duro

D13 · 03-27-2007, 05:59 AM

Neat, the opinions split just like my brain!

I'm a little leery of the 6.2, they very sensitive to being properly maintained.
Maybe I'll see if I can buy the FI 305 truck and when I wear out the motor swap in my spare 250. And I already have a non-integral head for it (BTDT).

Many thanks for the input, a lot of good material for my poor brain to chew over.

D13 · 03-27-2007, 06:01 AM

Yep, but it's a 3/4 so probably 14 bolt w/3.43 gears. Looking at 15-16mpg probably. But the truck is NICE.

03-23-2007, 06:04 AM	#1
D13 Registered User Join Date: Feb 2007 Location: Memphis MI Posts: 1,851	Help- which truck indecision! in the market for a driver, 70+ Michigan miles a day 5 days a week, 3 miles dirt 20 miles highway 10 miles city rest country. Really like 81-87 GMC and Chevy full size. looking for reasonable fuel mileage and long life, and not a 4wd. Already hav a 99 NBS tow beast so that's not really an issue. Found several possibilities and would like input. 84 1/2 ton 250 6cyl THM350 100k probably 3.08 or 3.23 10 bolt so could put 2.73 in it. Beleive this would get 17mpg or so as sitting, would look at swapping in 2004R and getting close to 20mpg. $3k + trans 84 1/2 ton 6.2 diesel auto 100k would this get 18mpg? $5k Anyone know what trans and rear end and ratio it is likely to have? 87 3/4 ton 5.0 probably a 700R4 60k I would bet 15-16 mpg probably 3.43 14-bolt so not much more highway gear available $5k All have decent to great bodies and interiors. I'm assuming that the tires etc are in eqivalent shape and that I have to add a posi to whatever I get. I'm very familiar with the 6cyl, SBC are common and I know nothing about diesels. All opinions welcome!

03-23-2007, 07:01 AM	#2
Blackstone Registered User Join Date: Dec 2006 Location: Central Maine Posts: 210	Re: Help- which truck indecision! I think the six-banger is called for in this situation. Considering the extra cost of diesel fuel, there isn't much to gain there.

03-23-2007, 07:35 AM	#3
rcbildr Registered User Join Date: Sep 2000 Location: Gold Bar, WA Posts: 1,216	Re: Help- which truck indecision! I think the diesel should get better than 18mpg, my 2wd diesel burb got at least 22mpg. My 4x4 diesel burb gets 19mpg. My guess is the truck has a 700R4. Not sure about the rear gears, of the 3 diesel rigs I have in my yard the 2 Suburbans have 4.10's and the 83 4x4 shortbed has 3.73. __________________ My Projects: 1960 GMC 1/2ton with 305 V6 (daily driver) 1963 Chevy 1/2ton 2wd...converting to 4x4 1967 Suburban 1/2ton 2wd My Girlfriends Projects 1985 Chevy Suburban 3/4ton 4x4 with 6.2L diesel, 4" lift, converted to TH-400, Warn Premium manual hubs, & Wildcat 315/75/R16 tires. (daily driver) 1978 Camaro Type LT with a Marine 350 & vortec heads, Rochester Carb, & roller cam 1978 Camaro Z28

03-23-2007, 07:45 AM	#4
grinch4om dang its hot Join Date: Nov 2006 Location: frankfort kentucky Posts: 1,349	Re: Help- which truck indecision! my vote for the six

03-23-2007, 09:23 AM	#5
old Rusty C10 Robert Olson Transport Join Date: Oct 2002 Location: recent transplant to NC USA Posts: 20,345	Re: Help- which truck indecision! id vote for the six myself a company i worked for had two FOrd vans the exact same E250 trucks one being diesel and one being the v8 gas and they got the same exact mileage __________________ Bob 1951 International running on a squarebody chassis "If a man's worth is judged by the people he associates himself with, then i am the richest man in the world knowing some of the fine people of this board" http://67-72chevytrucks.com/vboard/a...t.php?f=25&a=9 (you can review the site rules here!) PM Me for your vehicle/parts hauling needs in the North East US or see my Facebook page Robert Olson Transport Live each day to the fullest.. you never know when fate is going to pull the rug out from under you... I hate cancer!!

03-23-2007, 09:34 AM	#6
Slonaker Insert Witty Text Here Join Date: Oct 2002 Location: San Antonio, TX Posts: 3,415	Re: Help- which truck indecision! Since MPG seems to be an issue, I would buy the diesel or wait until you can find an '87. They are fuel injected, and have overdrive transmissions available. Slonaker __________________ '86 Chevy C10 (Sold 04/19/13 ) Stock '01 Silverado

03-23-2007, 01:27 PM	#7
D13 Registered User Join Date: Feb 2007 Location: Memphis MI Posts: 1,851	Re: Help- which truck indecision! The 87 is FI but 5.0. I need to find out if the 84 6.2 has O/D. They did not offer L6 with FI in the US, went 4.3 instead, would happily buy one except everyone seems to have replaced them with carb 5.7.

03-24-2007, 11:37 AM	#9
74 shortbed 406 Registered User Join Date: May 2005 Location: Bowling Green, Mo Posts: 204	Re: Help- which truck indecision! In my experience the six will drink just as much as a 350. I had a 74 with 350 turbo and 3.73 rear gears. The six got 10-13 depending on how hard you pushed it and the 350(stock rebuild) got 13-14 and it was more consistent on mileage. As for the 87, I have one now with tbi 350, 4x4, 465 tranny, and 3.08 gears and it is at 14-15. __________________ 1978 GMC K25 2002 Dodge Dakota R/T rc swb In need of some more goodies.

03-24-2007, 11:59 AM	#10
dswancutt Registered User Join Date: Jul 2003 Location: Franklin, NE Posts: 387	Re: Help- which truck indecision! The 250 sixes with intergral heads also have tendency to crack heads. That is what happened to my 79 with a six. I never got really good gas mileage with it, but the motor was shot. I would go with the 87 5.0. I have a 78 k-10 with a 5.0 running 3.73 gears and could get 13 mpg, and that was with a wore out carb.

03-24-2007, 02:19 PM	#11
Pyrotechnic Registered User Join Date: Feb 2007 Location: Austin, TX Posts: 3,930	Re: Help- which truck indecision! A 305 with 2.73's and a Turbo 350, or a 305 with 3.08's and a 700R4 are good combos for getting really great gas mileage. Possibly into the 20MPG range. The 700R4 will be the best bet since it's got a lower first gear to make take off easier, and it's got the lockup clutch which will help out a lot too. I would go for the 305.

03-24-2007, 02:57 PM	#12
Hoods69BadBowTie Chevys Kick A$$ Join Date: Jan 2005 Location: Zootown, MT Posts: 12,699	Re: Help- which truck indecision! I vote for the 5.0 motored truck. __________________ HOODS is what I answer too -'79, '77, '88 Pickup Sold, '85 Camaro, '83 T/A, '81,'83,'90 K5 Blazer All Sold -'79 3/4 ton "Big Yellow Bananna" Lifted 4spd. 39.5 TSL Swampers, The money Pit -'86 K5 Blazer Silverado 6.2 4" lift 35"s -'95 Ext. Cab Shorty 4" Tuff Country rolling 35" M/T's -'83 Monte Carlo T-Tops. 126,500 Original Miles -LATER I would rather push a Chevy then drive a ford!!

03-25-2007, 11:31 PM	#13
Duro5341 Registered User Join Date: Dec 2006 Location: Earth Posts: 239	Re: Help- which truck indecision! Personally I would go with the diesel, being your concerned about MPG, and long lasting.....you won't beat a diesel in these catagories I would guess the diesel would have a TH400, and a 14 bolt rear end....with the massive amount of torque the diesel will put out...these would hold it quite well. Also the diesel will be better if you ever decide to pull anything....you will have no problems Duro __________________ -1986 K10 LWB, 350 HD,TH400 3.08, 30 spline 10 bolt, with an Auburn Posi, 31" tires All original, second owner truck -1979 Monte Carlo, 350, 200r4, 3.73 posi -1987 GT T-top Mustang - slow moving project

03-27-2007, 05:59 AM	#14
D13 Registered User Join Date: Feb 2007 Location: Memphis MI Posts: 1,851	Re: Help- which truck indecision! Neat, the opinions split just like my brain! I'm a little leery of the 6.2, they very sensitive to being properly maintained. Maybe I'll see if I can buy the FI 305 truck and when I wear out the motor swap in my spare 250. And I already have a non-integral head for it (BTDT). Many thanks for the input, a lot of good material for my poor brain to chew over.

03-27-2007, 06:01 AM	#15
D13 Registered User Join Date: Feb 2007 Location: Memphis MI Posts: 1,851	Re: Help- which truck indecision! Yep, but it's a 3/4 so probably 14 bolt w/3.43 gears. Looking at 15-16mpg probably. But the truck is NICE.



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