tpi v,s, carb fuel economy ?

[starry5150]

I have to do somthing or I need to sell my rig just cant cutt the gas on it!! so I am looking for anything I can
Info : 1974 K5 blazer
dana 44 8 lug front with warn lock outs
rear 14bff both with 4.10s
semi built 350 chev ,750 rodchester carb,edelbrock intake, hei dist, accel suppercoil, headers cam unknown ,
350 turbo trans with B&M transpack
205 t-case
36X 14.50X15 super swamper radials
with that said I am getting about 4 miles to the gallon (yae :shaking: )
so I am wondering if I will get better fuel economy out of a tpi set up

[trkklr77]

other than the fact that your a blazer, you setup is very close to mine. ive got a l/b with 37" boggs, 4.56's, no o/d and a 700 hooley carb, i get 7-8mpg.

first off, both of these carbs are to big for a 350. mine stinks like unburned gas anytime i get on it. even though its a qjet its to big, get a 600-650.

im doing a tpi also and can not see geting less than 12mpg, even in my heavy ass l/b.

[MrWillys]

Tpi will really only help slightly by being more effecient. Where you'll really make a change would be switching to a transmission with a lockup converter, or maybe even an overdrive. I'm now getting over 15 mpg out my jeep with my TH350C. If I had the Blazer I'd have a 700R4 in that puppy....

[1972CJ5+1]

I would think you could get better than you are with what you have. How many MPG are you shooting for? Your carb may be a little big for your displacement without knowing your cam specs. Tuning alone will grap a few MPG. Remember that when your engine is tuned for greatest economy, it is not making the most HP, and also not running the cleanest smogwise. The original specs are a compromise of all these factors. If there is a dyno available nearby, you could save a bunch of money by having your setup tuned. A recurve of the distributor, rejetting of the carb, and some relatively cheap ( compared to FI upgrade ) ignition upgrade components should give you some decent gains all around. If you are looking for any more than 10 MPG total though, I think you are out of luck. The main advantages of the FI are the drivability at angles and the self adjustment to changing internal and external conditions. Both systems, properly tuned, will net very nearly the same economy. The FI setup will tend to adjust itself to keep it this way, while the carb setup will require more personal attention.

[starry5150]

I really want to stay away from the 700r had bad luck with them and they just scare me ! 12 miles per gallon would be great I have an advance kit in the distributor and new cap, rotor, coil is new, plugs are new .

[cherokeechief79]

ive been calling all around with the same questions.my big block chevy 91 cratemotor (only rated at 310 hp)is also only getting 4-5 mpg.it has peanut port heads .it was originally designed to put the stock fi intake and throttle body on it.i changed it to a edelbrock manifold and a holly 670 truck avenger.im now wondering if i was to go back to the stock intake and fuel inj ,if i could get 10 mpg or close.ive been told with any other type of aftermarket fi that i would have to put new heads and a new cam.i would do this but im also told that i would need new pistons to get a higher compression ratio.this last one is out of the question for me.
im also contemplating putting a straight 6 in for a while.if i could somhow get the exhaust to work for both i think i would do this.i could swap engs in a day.
hope we both find a way without gettin rid of our rigs

[1972CJ5+1]

Tpi will really only help slightly by being more effecient. Where you'll really make a change would be switching to a transmission with a lockup converter, or maybe even an overdrive. I'm now getting over 15 mpg out my jeep with my TH350C. If I had the Blazer I'd have a 700R4 in that puppy....

While I have only run manuals in my Jeeps, I am really suprised at the numbers you guys are getting. My last 304, with an edelbrock top end, headers, K&N cleaner and MSD ignition never got less than 15mpg on the highway. I only had 32s and 3.73s. While my new setup is a similarly built 360, with a bit more cam, my bottom end, 1tons and 39.5s is starting to scare me a bit. I was hoping to see the 15mpg on a non-smog motor properly tuned. I went 4.56s and should see the exact same RPM on the highway as before. My DD 86 Bronco tops in at 12 MPG loaded or not with a 5.0, and my CJ5 always got better milage. I hope my plans don't turn out to be a pipe dream.......

[j5]

1999 vortec 5.7 with stock GM computer in a 5k pound YJ with 35's and an nv4500 I get 12 mpg but I'm not shy about the go peddle. Keep in mind this is at 5000'.