advice

[tecky11]

i have a 1972 international 1210, basically a f250. it has a dana 44 rear end with 3.96 gears and i just wanted to get some opinions on how i can get some better mileage.
Engine 345 CI 2bbl 500 CFM carb
3 speed C6 tranny
LT245/85/16 tires
any ideas?

any help wold be aprecaited

[willett]

are you primarily driving highway or city?

[tecky11]

mostly city but i do some freeway

[78 Chevyrado]

I had a '73 caprice with a 400 in and a 2bbl carb. Dumb as this sounds, I got better mileage after I put a 4bbl on it. Lower (numerically) rear gears will help mileage.

[tecky11]

what kind of gears would u suggest?
how big of a 2bbl was on before and after with the 4 bbl

[84 400]

I have heard the same about 4bbl and better fuel millage. I am not sure exactly why as the secondaries would consume more fuel when open but maybe the primaries are smaller then that on the stock 2bbl so maybe it is more efficient??

[tecky11]

What size carb would you suggest and whay else would I have to change

[dswancutt]

I think you are asking a lot from your IH. The 345 IH motor is basically a truck motor and is designed to lug. Trust me, I have one in a grain truck and it will pull like a freight train but eats gas, I'm lucky if I get 5 MPG. Changing the rear in will help a little and the 4 barrel might also help.
Weight is also a problem, a 345 IH motor weights 641 lbs without accessories, more than a big block chevy.

[Pyrotechnic]

An Edelbrock 650 would be a decent carb for it. You would need a new intake manifold to go to a 4 barrel though.

Headers, and a free flowing exhaust will also help. Again, I'm not sure about the availability of headers for these trucks. If your existing exhaust is restrictive, a new true dual exhaust with an H pipe and some free flowing mufflers could help.

Also, a free flowing air cleaner with a cold air source can also help.

[tecky11]

I have true dual from manifold back
What kind od fuel increase would I get.all I really need is 2-3 mpg

[tecky11]

I have true dual from manifold back
What kind od fuel increase would I get.all I really need is 2-3 mpg

[kevinr1970]

Originally Posted by 84 400

I have heard the same about 4bbl and better fuel millage. I am not sure exactly why as the secondaries would consume more fuel when open but maybe the primaries are smaller then that on the stock 2bbl so maybe it is more efficient??

To the best of my knowledge (and I wouldn't put any bets on this!) a 2bbl carb is larger than the primaries on a 4bbl carb. So in theory if you keep your foot out of it you will get better mileage.

[dswancutt]

Originally Posted by kevinr1970

To the best of my knowledge (and I wouldn't put any bets on this!) a 2bbl carb is larger than the primaries on a 4bbl carb. So in theory if you keep your foot out of it you will get better mileage.

I don't have the numbers, but IH used Holley carbs both 2 & 4 bbl. The manual choke 2 bbl is basically the front half of a 4 barrel.
You have to remember that a 3/4 IH pickup is a heavy duty pickup and gas mileage was not there (IH) main concern.
One thing to consider doing is converting to a pertronix electronic distributor. My IH runs way better than when it had points and condenser. And truthfully, setting the points on a IH just plain sucks.

[tecky11]

where do i get the distibutor and how di set them?