Happy Happy -New TBI mileage - The 1947 - Present Chevrolet & GMC Truck Message Board Network

VinceY · 07-24-2007, 12:31 PM

Just had a new crate 350 motor (TBI) and a 700R4 tranny put into my 72 Blazer. Also a transfer case replacement with a rebuilt early 90s style t-case.
No pictures, too busy driven her.

The mileage was at 12 mpg max. with the old 350/T350 -250 tcase.

New TBI got me 18.5 mpg (combination highway and foothills gravel gas plant roads). Had a bikini top on the whole time - wonder if that helps a bit??

Very Happpppppy.

Musclerodz · 07-24-2007, 01:07 PM

What gears in the rear and what size tires? I will be happy if I get around the same

Mike

VinceY · 07-24-2007, 04:25 PM

Quote:

Originally Posted by Musclerodz

What gears in the rear and what size tires? I will be happy if I get around the same

Mike

3.73 gear ratio and 30" tires.

vtblazer · 07-24-2007, 05:02 PM

Not to mention the better power/throttle feel.

Better starts, no more dieseling...always a good mod!

Chris27 · 07-25-2007, 02:10 PM

Vince,

Congrats on getting the K5 back on the road! I knew you'd like the drivtrain swap. Mine had similar results, went from 9mpg to 18mpg, but my stock drivetrain was pretty worn out. Enjoy the new mileage and driveabilty

Rokcrln · 07-25-2007, 06:40 PM

That is great I am glad you like the results. I for one have EFI of one form or another on everything I build (except Low Buck for now) and love it. I can't wait to slap in a 6.0 and AOD into Low Buck one day soon. Even on a tired motor if you pull the carb and drop on a simple TBI system it really wakes it up. In my 71 SWB I hope to get in th elow 20's with my set up but I have awhile to before I will find out

Kevin
LFD Inc.

mister.freeze · 07-29-2007, 06:06 PM

373 rear+ 35" tires+ 383 stoker+ 700r4+ Holley ProJection TBI= 9.16mpg uphill, downhill, headwind, tailwind, trailer and without. BUT I have 400+ hp... Maybe I should sell the drivtrain and try something else?

LUV2XCLR8 · 07-29-2007, 10:15 PM

krue · 07-29-2007, 10:28 PM

How much does the engine setup cost to go TBI? I wouldn't mind getting that mileage in my truck.

VinceY · 07-30-2007, 10:14 AM

Quote:

Originally Posted by krue

How much does the engine setup cost to go TBI? I wouldn't mind getting that mileage in my truck.

I am not the right guy to answer this as I had a newer style transfer case installed also which took abit of modification time and I did not have time to do it my self and paid someone to do all of it. Some of the other members would probably have a better price guideline.

Chris27 · 07-31-2007, 02:11 PM

Here's a breakdown of the costs for my TBI swap (Cdn $):
Used '92 TBI 350 = $800 (complete with all accesories and sensors/computer)
Rebuilt 700R4 tranny = $1200
AA short output shaft = $300
TBI wiring harness = $600 (c/w speedo cable to VSS adapter)
90 Blazer fuel tank = $200 (new aftermarket)
Fuel pump = $75 (new from GM)
Those are all the major components figure on another $500 for assorted stuff (hoses fittings etc.) and it comes out to $3675.00. I actually spent closer to $5000, but I upgraded to 3/4 ton at the same time. The cost will also depend on what you can find used, or free. VtBlazer might chime in, IIRC he bought a complete running '88 Blazer and swapped everything over. Pricy, but for me it was worth it.

07-24-2007, 12:31 PM	#1
VinceY Just need a couple more parts. Join Date: Jan 2005 Location: Calgary, Alberta, Canada Posts: 470	Happy Happy -New TBI mileage Just had a new crate 350 motor (TBI) and a 700R4 tranny put into my 72 Blazer. Also a transfer case replacement with a rebuilt early 90s style t-case. No pictures, too busy driven her. The mileage was at 12 mpg max. with the old 350/T350 -250 tcase. New TBI got me 18.5 mpg (combination highway and foothills gravel gas plant roads). Had a bikini top on the whole time - wonder if that helps a bit?? Very Happpppppy. __________________ --------------------------------------------------- 1947 Studebaker M5 project to match the camping trailer. 1950 Chev 4x4 Pickup 1958 Shasta Airflyte Travel trailer (fresh restoration) 1971 C/10 Pickup(Frame off Restoration) 1972 K5 Blazer CST (Daily Driver & My Company Truck) 1976 Honda CB750 Bobber 1988 Jaguar XJ12

07-24-2007, 01:07 PM	#2
Musclerodz Senior Member Join Date: Aug 2005 Location: OKC, OK Posts: 2,365	Re: Happy Happy -New TBI mileage What gears in the rear and what size tires? I will be happy if I get around the same Mike __________________ Mike Redpath

07-24-2007, 05:02 PM	#4
vtblazer Registered User Join Date: Oct 2003 Location: Central Vermont Posts: 8,538	Re: Happy Happy -New TBI mileage Not to mention the better power/throttle feel. Better starts, no more dieseling...always a good mod!

07-25-2007, 02:10 PM	#5
Chris27 Blazerless Join Date: Nov 2006 Location: Kelowna, BC, Canada Posts: 274	Re: Happy Happy -New TBI mileage Vince, Congrats on getting the K5 back on the road! I knew you'd like the drivtrain swap. Mine had similar results, went from 9mpg to 18mpg, but my stock drivetrain was pretty worn out. Enjoy the new mileage and driveabilty __________________ 72' K5 Blazer 4x4 350TBI/700R4/NP205 3/4 ton diffs. Daily driver. SOLD 69' Beaumont 388/700R4 11.70@116 77' Bronco, Wife's mall cruiser/poser 4x4. Capable but too pretty to go offroad.

07-25-2007, 06:40 PM	#6
Rokcrln Senior Member Join Date: Jul 2005 Location: Winters Ca. 95694 Posts: 4,843	Re: Happy Happy -New TBI mileage That is great I am glad you like the results. I for one have EFI of one form or another on everything I build (except Low Buck for now) and love it. I can't wait to slap in a 6.0 and AOD into Low Buck one day soon. Even on a tired motor if you pull the carb and drop on a simple TBI system it really wakes it up. In my 71 SWB I hope to get in th elow 20's with my set up but I have awhile to before I will find out Kevin LFD Inc.

07-29-2007, 06:06 PM	#7
mister.freeze Registered User Join Date: Dec 2003 Location: Houston, TX Posts: 734	Re: Happy Happy -New TBI mileage 373 rear+ 35" tires+ 383 stoker+ 700r4+ Holley ProJection TBI= 9.16mpg uphill, downhill, headwind, tailwind, trailer and without. BUT I have 400+ hp... Maybe I should sell the drivtrain and try something else? __________________ '72 K5, known as 'the Fox.'

07-29-2007, 10:15 PM	#8
LUV2XCLR8 The LuvShack Garage Join Date: Jan 2004 Location: Maple Grove, TN (West Side) Posts: 30,475	Re: Happy Happy -New TBI mileage __________________ Owner/Op: "TN Classic Transport Carriers" The Toy: "Square Vette" 72 Hybrid Blazer Toy Barn: "LuvShack" 40 x 60 x 20 Shop Big Piggy: "Goliath" 07 Kodiak C4500 Lil Piggy:"Maddy" 88 Silverado 3500 Hauler: "Feathers" 14 Aluma 8218T

07-29-2007, 10:28 PM	#9
krue Designated A-hole! Join Date: Mar 2003 Location: South Mississippi Posts: 36,450	Re: Happy Happy -New TBI mileage How much does the engine setup cost to go TBI? I wouldn't mind getting that mileage in my truck. __________________ "If it ain't broke, fix it 'til it is!" Being stupid ain't illegal. We're Still Debt Free Except for the House!!! www.daveramsey.com 70 GMC SWB Stepside project "Green Booger" soon to be 6.0l/4l80e 93 S-10 "Poppaw's Truck"

07-31-2007, 02:11 PM	#11
Chris27 Blazerless Join Date: Nov 2006 Location: Kelowna, BC, Canada Posts: 274	Re: Happy Happy -New TBI mileage Here's a breakdown of the costs for my TBI swap (Cdn $): Used '92 TBI 350 = $800 (complete with all accesories and sensors/computer) Rebuilt 700R4 tranny = $1200 AA short output shaft = $300 TBI wiring harness = $600 (c/w speedo cable to VSS adapter) 90 Blazer fuel tank = $200 (new aftermarket) Fuel pump = $75 (new from GM) Those are all the major components figure on another $500 for assorted stuff (hoses fittings etc.) and it comes out to $3675.00. I actually spent closer to $5000, but I upgraded to 3/4 ton at the same time. The cost will also depend on what you can find used, or free. VtBlazer might chime in, IIRC he bought a complete running '88 Blazer and swapped everything over. Pricy, but for me it was worth it. __________________ 72' K5 Blazer 4x4 350TBI/700R4/NP205 3/4 ton diffs. Daily driver. SOLD 69' Beaumont 388/700R4 11.70@116 77' Bronco, Wife's mall cruiser/poser 4x4. Capable but too pretty to go offroad.



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.