• To ALL forum users - As of late I have been getting quite a few private messages with questions about build ups here on the forum, or tech questions about your personal project. While I appreciate the interest, sending me a private message about these topics distracts from, and undermines the purpose of having a forum here. During the day I wear many hats as a small business owner-operator and I work tirelessly to provide the absolute best service possible to you, our valued customer. When I created this forum I rounded up some of the best minds I knew so that any tech question you might have could be asked and answered by either myself or one of my highly experienced moderators, this way the next time this same question is asked the answer can be easily found and utilized by the next IH enthusiast having the same question. This allows me the freedom to run the day to day operations of the business and minimize the impact to shipments and shop activities that these distractions can cause. It is of the up most importance for me to complete the daily tasks in order to best take care of you our customer, all the while providing you a forum to get the level advice and input you have come to expect and deserve from the premier IH shop in the country.

    So with that I ask that anyone with a question about one of our build ups or a general tech question to please use the forum as it was intended. I am absolutely available by telephone to answer your questions as well but at times may direct you back to our website to better field your question or questions. Most other private messages I will be glad to answer for you.

    Thank you for your understanding.

    Jeff Ismail

Considering upgrading 345 with FI kit sold on here.. is it worth it?


New member
I have a customer wanting to get better mileage out of her 78 Scout 345 motor.. She is thinking a GM engine swap but I am trying to talk her out of it because of cost. I am thinking the fuel injection upgrade option May be her best choice. The Scout stays original, saves a lot of time and money and it May solve her issue versus the swap. I am willing and able to do either but I truly would like more info on any available specs if I were to do the fuel injection upgrade.. Anyone know an estimated mpg rating? Even a close guess? What about changes in horsepower and torque? I need numbers to present to her to support my suggestion. I would love to take the work and surely tons of labor I will earn from doing the swap and it actually sounds fun.. But I believe in doing whats truly best and most efficient for my customers. Any help would be greatly appreciated. Also any input. First time here.. So be gentle.. Lol


Active member
The first question that comes to mind is "what transmission is behind that IH 345?" if it's the automatic torqueflite 727, then you're limited to a 3 speed without overdrive.

Second question is "doesn't the 78 need to smogged?" if so, you might be limited to what you can swap in & out for a powerplant. I'm not exactly sure how or if the hamilton efi will pass the visual inspection of the smog natzi. I've heard mixed reviews on this depending on state and counties and who is doing the testing. Bill hamilton could offer some better answers to this than me on the subject

my own experience with the hamilton efi is that it's a plug and play install, with the minor exception of welding in an o2 sensor threaded bung into the collector of the exhaust plumbing. Last year, I had helped a friend, who at the time was mechanically challenged on working on his 69 Scout 800 and installed the complete efi kit. In comparing the cost of this kit to a motor swap, it will be cheaper. Not sure of the exact mpg improvement, since this install was on someone else's vehicle. But once completed, consistent easy start every time, in comparison to the old carb set up, no matter the altitude. Also easier to maintain. Also, this complete efi kit is something that I'm planning on installing into both my scouts with ih345 motors

motor swap entails the cost of what ever chevfurdoper flavor of choice in engine, transmission, transfer case, adapters if needed, and fabrication of new mounts for all these new components. Along with new prop shafts

the IH motors are low revving anorexic torque working motors and not exactly a speed demon like the big 3.

On alternative that is somewhat common with keeping the ih345 power plant is to swap the transmission/t-case and install a GM 700r4 with adapters to the ih345. If keeping the Scout axles, then a passenger side drop t-case needs consideration to adapt to the 700r4 transmission. This route will offer an overdrive automatic if that's a preference. Or go with adapting a manual gear shifter, like nv4500 or some other manual overdrive.


New member
Yes, sorry for lack of info given. It has the ih345 with the 727 torqueflite auto tranny. The vehicle is all original. I also wonder if another simple solution for freeway speed would be do the FI upgrade, headers, cam and then re-gear the differentials?they don't need smog, I am advising just to avoid any future possible issues or consequences if we do a newer (I am thinking the gen II l31 5.7 liter vortec w/4l60e/700r4 or gen iii lm7 5.3 liter vortec w/4l60e) GM full engine, trans, t-case swap or atleast the first two and keep all smog parts intact and installed and for her to go ahead and deal with the referee and get it done legally and legitimately but in truth she can probably get away with it by not saying anything or reporting the swap. But in my experience or atleast in my personal experiences shortcuts or even the smallest bit of "dishonesty" always finds a way to bite me in the hind quarters. She seems dead set on the swap.. But I wonder would the ih395 swapped for the ih345 help? In truth I know next to nothing about scouts or anything International built so I am trying to hit the ground running by doing a ton of reading and research.. Also hence why I decided to post on here and ask the more experienced and more passionate IH fans. Again, any and all input will be greatly appreciated.


New member
Last note.. Tpycially yes the car would need to be smogged, but her husband is over seas right now in the military and the car is and will most likely remain registered out of state where smog is not required. But, again, if they get caught living here and such and ends up required to get a smog and/or register it here in California then that is where it will bite them in the rear. Which is why I am pushing gently for them to do it right the first time.. Is always the easiest and best in my experience.


Active member
Yea, when it comes to the current smog law of 76 and newer vehicles, I would be having reservations with any modified add ons, much less a motor swap that didn't originally come in the particular vehicle. With that being said, as much of an improvement hamilton efi is to these ole IH motors, I don’t think the kits are carb compliant(or for what ever coding it is for each state). Again, mr hamilton can give ya better answer to this subject than I could, when it it comes to smoging and the efi kit.

Side note - I know one guy who lives in san francisco that has a 78 that was inherited. Originally it came with an IH 4 banger. The kid took it down to a shop in san jose, probably 10 years ago, and did a motor swap to an IH 304. Now he can't get it to smog. The smog natzi ref's won't have anything to do with it and claim that it will not ever pass smog again.

Anyways, one swap you just might be able to get away with, that shouldn't have anything to do with smog related compliance, is adapting a 700r4 trans and t-case behind the IH 345. That will help some with highway fuel economy.


The hamilton kit isn't carb certified.

There is not much, if any, difference between a perfectly tuned carb and efi just going down the highway. The efi will run more consistently year in and year out however which can save quite a lot of gas over time. Bottom line, if the goal is to save money via mpg it will take years to just break even on the initial investment.

I don't know about cali, but in Colorado anyone that that lives or works in one of the designated areas must have emissions regardless of the state of registration. All the cop has to do is ask the wrong questions and you're sunk.

Military that are legal residents of California (taxes, voting, and/or home ownership...) can also be charged with tax evasion if they get caught registering vehicles out of state. Rarely happens, but it's possible.

Bill USN-1

F.I. Moderator
Being prior military stationed at lemoore with my 76 Scout, I have dealt with the smog issues.
If you would like to discuss and if you have specific hamilton fuel injection questions just give a call.
360 969-2925
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Active member
The route I went was with a Holley 390cfm 4 barrel carb. The strategy was to tune the primaries in the carb for good mpg under normal driving and the secondaries for lots of power when needed. So far this setup has achieved a best full tank mpg of just a hair under 15. This is mixed driving as I haven't taken the Scout on a long freeway drive yet. Best ever with the 2210 was 12.5 mpg.

Interestingly removing the top has cost almost 2 mpg. Where I'm going with this is that I think the most bang for the buck can be had by improving the aerodynamics of the vehicle. A flexible front air dam would probably help mpg a lot.