71 c10 4.3 - The 1947 - Present Chevrolet & GMC Truck Message Board Network

cblock · 04-10-2015, 04:46 AM

whats up everibody, I just got a1971 c10 longbed with a 350 eng /350 tranny combo, and I'm seriously considering putting a 4.3 v6 with an automatic overdrive transmission from a mid 90's s10 blazer, i use to have a 1978 blazer 4x4 and it was a gas guzzler. I've owned several 90's chevy v8 and they're ok, but I want a truck that I can drive everyday. any advice or prior experiences will be greatly appreaciated.thanks.

hugger6933 · 04-10-2015, 07:13 AM

Go back with the 350 and the overdrive. I am a s-10 man or used to be I built tons of them over the years and owned one of every year model through the whole run of them[I built a lot of S-10's] While the 4.3 is a good motor its basic problem in the full sized truck [and the S-10] was it was underpowered. I have built in younger days quite a few V-8 S-10's and if the motor was stock it would always get better mileage than the V-6 counterpart because it didn't have to work as hard to do the job. That is the main reason I say use a 350 with similar equipment[like a TBI] and the overdrive trans. That is where the main improvement in gas mileage will be found. Jim

**special-K** · 04-10-2015, 07:53 AM

Do yourself a favor and find a good 307. Slap a small 4bbl on and get even better mileage.

I see this was your first post, welcome to the site!

**70cst** · 04-10-2015, 09:11 AM

Hey cblock ...

to the forums and

from Ohio.

I would luv to see some pics of your ride.

Longhorn 70 · 04-10-2015, 10:10 AM

Welcome to the board cblock !

Quote:

Originally Posted by hugger6933

Go back with the 350 and the overdrive. I am a s-10 man or used to be I built tons of them over the years and owned one of every year model through the whole run of them[I built a lot of S-10's] While the 4.3 is a good motor its basic problem in the full sized truck [and the S-10] was it was underpowered.

I agree with Jim. I have owned good running 4.3s and while they were super reliable, they sucked wind. A good running 350 will get better mileage in heavier square vehicles. In my opinion, the reason our trucks get poor fuel economy is due to their frontal area and gear ratios.

**RenoKeene** · 04-10-2015, 02:20 PM

Agreed with all above. 4.3 is not enough motor for a full size truck and they don't get good mpg anyway.

rotten67 · 04-10-2015, 09:47 PM

I have a 96 c1500 with a 4.3 and a 5 speed gets 15 mpg in town. seems to have decent power.

**c10-72 II** · 04-11-2015, 12:30 AM

I was thinking the same thing but adding a turbo. Like the old school syclones and typhoons.

Shaky · 04-11-2015, 05:37 AM

Quote:

Originally Posted by rotten67

I have a 96 c1500 with a 4.3 and a 5 speed gets 15 mpg in town. seems to have decent power.

I too have a '96 4.3. It has a roller cam, dual cats, port injection, and the Vortec heads. I was never impressed with the earlier 4.3s but this one does pretty good on the power/mileage thing.

Use the search function. There are several other 4.3 threads on this site where this has been talked about extensively.

04-10-2015, 04:46 AM	#1
cblock Registered User Join Date: Apr 2015 Location: chulavista ca Posts: 28	71 c10 4.3 whats up everibody, I just got a1971 c10 longbed with a 350 eng /350 tranny combo, and I'm seriously considering putting a 4.3 v6 with an automatic overdrive transmission from a mid 90's s10 blazer, i use to have a 1978 blazer 4x4 and it was a gas guzzler. I've owned several 90's chevy v8 and they're ok, but I want a truck that I can drive everyday. any advice or prior experiences will be greatly appreaciated.thanks. Last edited by cblock; 04-10-2015 at 04:48 AM. Reason: spelling

04-10-2015, 07:13 AM	#2
hugger6933 Registered User Join Date: Oct 2008 Location: Marianna Arkansas Posts: 7,257	Re: 71 c10 4.3 Go back with the 350 and the overdrive. I am a s-10 man or used to be I built tons of them over the years and owned one of every year model through the whole run of them[I built a lot of S-10's] While the 4.3 is a good motor its basic problem in the full sized truck [and the S-10] was it was underpowered. I have built in younger days quite a few V-8 S-10's and if the motor was stock it would always get better mileage than the V-6 counterpart because it didn't have to work as hard to do the job. That is the main reason I say use a 350 with similar equipment[like a TBI] and the overdrive trans. That is where the main improvement in gas mileage will be found. Jim

04-10-2015, 07:53 AM	#3
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,863	Re: 71 c10 4.3 Do yourself a favor and find a good 307. Slap a small 4bbl on and get even better mileage. I see this was your first post, welcome to the site! __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~ Last edited by special-K; 04-10-2015 at 09:50 AM.

04-10-2015, 09:11 AM	#4
70cst Senior Member Join Date: Feb 2001 Location: New Madison, Ohio Posts: 21,339	Re: 71 c10 4.3 Hey cblock ... to the forums and from Ohio. I would luv to see some pics of your ride. __________________ A husband can be right...or...A husband can be happy. 67-72 Chevy and GMC Trucks...The Classic Truck for the Classic Folk. 1970 CST Two tone green, 402BB, 400 Automatic, Tach, Buckets, AC, AM-FM, Tilt, GM CB, GM 8 Tract, LWB, etc JOHN 17:3...The better side of "LIFE" Remember: Everyday is a good day...Some are just gooder!

04-10-2015, 02:20 PM	#6
RenoKeene Florida Edition Join Date: Oct 2010 Location: Fruitland Park, FL Posts: 4,011	Re: 71 c10 4.3 Agreed with all above. 4.3 is not enough motor for a full size truck and they don't get good mpg anyway. __________________ 70 GMC Short Stepside "Rose"-An American Beauty: Factory 402/TH400, AM/FM, AC, Tilt, Tach, Buckets, Posi, PS, PB, 3-5 Drop, Complete Resto-Rod 67 C-20 Slant Back Wrecker "Mad Max" 67 C-10 Ratrod "Step-N-Wolf" 71 Serro Scotty Sportsman camper "Scotty" 97 LT1 Z28 "The Hornet" Link to more pics of "Rose" http://67-72chevytrucks.com/vboard/a...p?albumid=1684 Check out my "Cheap Tricks" thread and add to it if you can, lots of good info there. http://67-72chevytrucks.com/vboard/s...d.php?t=489394

04-10-2015, 09:47 PM	#7
rotten67 Registered User Join Date: Aug 2013 Location: cheyenne wy Posts: 31	Re: 71 c10 4.3 I have a 96 c1500 with a 4.3 and a 5 speed gets 15 mpg in town. seems to have decent power.

04-11-2015, 12:30 AM	#8
c10-72 II Active Member Join Date: Sep 2013 Location: Elk Grove Village IL Posts: 152	Re: 71 c10 4.3 I was thinking the same thing but adding a turbo. Like the old school syclones and typhoons.



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