What kind of HP and MPG with a mild 4.3

t-scene · 10-11-2008, 05:32 PM

Im thinking about getting a GM 4.3L crate engine to swap in my 98 in place of the 2.2L I was thinking about just adding a cam, headers, cold air intake tune the computer and MSD Coil/Wires and changing the rear end gear from 4.10 to 3.73 or so and
use this cam ((( http://www.cranecams.com/?show=browseParts&lvl=2&prt=5&Vehicle_Type=Auto&Cy linders=6&Engine_Make=CHEVROLET&Year=2003&Engine_S ize=4.3%20L&partNumber=1439721&partType=camshaft ))) leaving everthing else stock but run a e-fan and open exhaust

t-scene · 10-11-2008, 05:36 PM

what kind of MPG and HP would I be looking at

Renegade_Z · 10-12-2008, 12:19 AM

Do you have a lead foot?

t-scene · 10-12-2008, 01:37 AM

lol some what from time to time but not constant

lesterl · 10-12-2008, 01:41 AM

13-25 perhaps. I used to get upwards of 25 on my 98 jimmy with a 4.3l and auto 4x4 babying the hell outa it, when you are running them hard all the time the MPG does suffer.

1fast4by · 10-12-2008, 01:46 AM

I get about 10mpg

Premium 93

Mine may not be considered "mild" though\

*When mine was "mild" though Heads, full bolt ons, FMU, tune, and a few others, I was making 232rwhp, and getting about 16mph average

lesterl · 10-12-2008, 01:50 AM

Is she a screamer now? What gearing did you use?

1fast4by · 10-12-2008, 01:54 AM

Geared 3.42, stock 4x4, but through Richmond...Runs average of mid 12s...

SLOW, I'll drop in the 11s befor Im done with the V-6 4x4....

lesterl · 10-12-2008, 01:55 AM

I had 3.73's stock on my Jimmy and that was an awesome rig, the 98 blazer I drove for a while had 3.42's and it was a bit of a dog and got 2-3 mpg less.

1400th post!

1fast4by · 10-12-2008, 01:58 AM

I prefer my 3.42s on the cam and bottle....

t-scene · 10-12-2008, 11:04 AM

wow that quick for a 4x4

lesterl · 10-12-2008, 11:10 AM

Kewl!!!!!!!!!

Renegade_Z · 10-13-2008, 12:35 AM

So there you go. I get shitty gas milage. Maybe 15 in the city and i baby it. Gonna change the cam now hope the milage doesnt suck more.

lesterl · 10-13-2008, 12:39 AM

15 in the city is bout normal for what I was gettin, thats a v6 auto for ya. Could be worse, could be 15 city 15 hwy. :-)

circa · 10-13-2008, 03:08 AM

will you be using an automatic or a manual?
my stock 97 4.3/fullsize nv3500
I destroyed my sister's RSX Type-S, which started to catch up around 60 but was still 4-5 car lengths behind.

all i have is a ebay intake and a TB spacer. 30 mpg hwy never seen below 27 mixed/mostly city unless i avoid 5th gear and do light to lights... then its 22mpg

Renegade_Z · 10-14-2008, 01:05 AM

Lol yup the auto sucks on mileage. Not to jack the thread or nuthin but what do yall think im gonna get out of the 266AHR and some head work? ie bigger valves, 1.6 rockers etc? Guy at the machine shop told me to go with the smaller cam if i wasnt gonna run a converter? Thanks

t-scene · 10-14-2008, 06:51 PM

mine will be with a auto

circa · 10-14-2008, 07:11 PM

probably 3-5 points under a normal v6 auto then.
of course mpg depends on driving habits and what not.

whenever your foot isnt in it.... do some hypermiling!!

10-11-2008, 05:32 PM	#1
t-scene Registered User Age: 20 Join Date: Jul 2008 Posts: 89 Location: User is: OffLine	What kind of HP and MPG with a mild 4.3 Im thinking about getting a GM 4.3L crate engine to swap in my 98 in place of the 2.2L I was thinking about just adding a cam, headers, cold air intake tune the computer and MSD Coil/Wires and changing the rear end gear from 4.10 to 3.73 or so and use this cam ((( http://www.cranecams.com/?show=browseParts&lvl=2&prt=5&Vehicle_Type=Auto&Cy linders=6&Engine_Make=CHEVROLET&Year=2003&Engine_S ize=4.3%20L&partNumber=1439721&partType=camshaft ))) leaving everthing else stock but run a e-fan and open exhaust Last edited by t-scene : 10-11-2008 at 05:35 PM.
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10-11-2008, 05:36 PM	#2
t-scene Registered User Age: 20 Join Date: Jul 2008 Posts: 89 Location: User is: OffLine	Re: What kind of HP and MPG with a mild 4.3 what kind of MPG and HP would I be looking at
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10-12-2008, 12:19 AM	#3
Renegade_Z Registered User Join Date: Apr 2008 Posts: 242 Location: Fairfax City, Virginia User is: OffLine	Re: What kind of HP and MPG with a mild 4.3 Do you have a lead foot?
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10-12-2008, 01:37 AM	#4
t-scene Registered User Age: 20 Join Date: Jul 2008 Posts: 89 Location: User is: OffLine	Re: What kind of HP and MPG with a mild 4.3 lol some what from time to time but not constant
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10-12-2008, 01:41 AM	#5
lesterl Wire Splicin Fool :-) Age: 29 Join Date: May 2008 Posts: 1,735 Location: Kansas City Area User is: OffLine	Re: What kind of HP and MPG with a mild 4.3 13-25 perhaps. I used to get upwards of 25 on my 98 jimmy with a 4.3l and auto 4x4 babying the hell outa it, when you are running them hard all the time the MPG does suffer.
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10-12-2008, 01:46 AM	#6
1fast4by No bags, still DRAGS... Age: 25 Join Date: Mar 2004 Posts: 9,233 Location: Green Hills/Nashville User is: OffLine	Re: What kind of HP and MPG with a mild 4.3 I get about 10mpg Premium 93 Mine may not be considered "mild" though\ When mine was "mild" though Heads, full bolt ons, FMU, tune, and a few others, I was making 232rwhp, and getting about 16mph average Last edited by 1fast4by : 10-12-2008 at 01:50 AM.*
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10-12-2008, 01:50 AM	#7
lesterl Wire Splicin Fool :-) Age: 29 Join Date: May 2008 Posts: 1,735 Location: Kansas City Area User is: OffLine	Re: What kind of HP and MPG with a mild 4.3 Is she a screamer now? What gearing did you use?
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10-12-2008, 01:54 AM	#8
1fast4by No bags, still DRAGS... Age: 25 Join Date: Mar 2004 Posts: 9,233 Location: Green Hills/Nashville User is: OffLine	Re: What kind of HP and MPG with a mild 4.3 Geared 3.42, stock 4x4, but through Richmond...Runs average of mid 12s... SLOW, I'll drop in the 11s befor Im done with the V-6 4x4.... Last edited by 1fast4by : 10-12-2008 at 01:55 AM.
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10-12-2008, 01:55 AM	#9
lesterl Wire Splicin Fool :-) Age: 29 Join Date: May 2008 Posts: 1,735 Location: Kansas City Area User is: OffLine	Re: What kind of HP and MPG with a mild 4.3 I had 3.73's stock on my Jimmy and that was an awesome rig, the 98 blazer I drove for a while had 3.42's and it was a bit of a dog and got 2-3 mpg less. 1400th post! Last edited by lesterl : 10-12-2008 at 01:56 AM. Reason: 1400th post!
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10-12-2008, 01:58 AM	#10
1fast4by No bags, still DRAGS... Age: 25 Join Date: Mar 2004 Posts: 9,233 Location: Green Hills/Nashville User is: OffLine	Re: What kind of HP and MPG with a mild 4.3 I prefer my 3.42s on the cam and bottle....
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10-12-2008, 11:04 AM	#11
t-scene Registered User Age: 20 Join Date: Jul 2008 Posts: 89 Location: User is: OffLine	Re: What kind of HP and MPG with a mild 4.3 wow that quick for a 4x4
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10-12-2008, 11:10 AM	#12
lesterl Wire Splicin Fool :-) Age: 29 Join Date: May 2008 Posts: 1,735 Location: Kansas City Area User is: OffLine	Re: What kind of HP and MPG with a mild 4.3 Kewl!!!!!!!!!
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10-13-2008, 12:35 AM	#13
Renegade_Z Registered User Join Date: Apr 2008 Posts: 242 Location: Fairfax City, Virginia User is: OffLine	Re: What kind of HP and MPG with a mild 4.3 So there you go. I get shitty gas milage. Maybe 15 in the city and i baby it. Gonna change the cam now hope the milage doesnt suck more.
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10-13-2008, 12:39 AM	#14
lesterl Wire Splicin Fool :-) Age: 29 Join Date: May 2008 Posts: 1,735 Location: Kansas City Area User is: OffLine	Re: What kind of HP and MPG with a mild 4.3 15 in the city is bout normal for what I was gettin, thats a v6 auto for ya. Could be worse, could be 15 city 15 hwy. :-)
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10-13-2008, 03:08 AM	#15
circa Registered Abuser Age: 21 Join Date: Jun 2006 Posts: 980 Location: Puyallup, Wa User is: OffLine	Re: What kind of HP and MPG with a mild 4.3 will you be using an automatic or a manual? my stock 97 4.3/fullsize nv3500 I destroyed my sister's RSX Type-S, which started to catch up around 60 but was still 4-5 car lengths behind. all i have is a ebay intake and a TB spacer. 30 mpg hwy never seen below 27 mixed/mostly city unless i avoid 5th gear and do light to lights... then its 22mpg
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10-14-2008, 01:05 AM	#16
Renegade_Z Registered User Join Date: Apr 2008 Posts: 242 Location: Fairfax City, Virginia User is: OffLine	Re: What kind of HP and MPG with a mild 4.3 Lol yup the auto sucks on mileage. Not to jack the thread or nuthin but what do yall think im gonna get out of the 266AHR and some head work? ie bigger valves, 1.6 rockers etc? Guy at the machine shop told me to go with the smaller cam if i wasnt gonna run a converter? Thanks
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10-14-2008, 06:51 PM	#17
t-scene Registered User Age: 20 Join Date: Jul 2008 Posts: 89 Location: User is: OffLine	Re: What kind of HP and MPG with a mild 4.3 mine will be with a auto
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10-14-2008, 07:11 PM	#18
circa Registered Abuser Age: 21 Join Date: Jun 2006 Posts: 980 Location: Puyallup, Wa User is: OffLine	Re: What kind of HP and MPG with a mild 4.3 probably 3-5 points under a normal v6 auto then. of course mpg depends on driving habits and what not. whenever your foot isnt in it.... do some hypermiling!!
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