Chevy Engine in 74 international travelall

[Abelal]

So I have a travelall with a 392 v8 in it and it’s a gas guzzler. I am in California and gas is very expensive. I want to take the 392 out and keep it stock on the side and drop a Chevy engine in there keeping the same transmission using an adapter plate. My goal is to get at least 15mpg. I have a Chevy 350 from a 69 c10. Is it worth cleaning up an older engine or getting one out of a 2011 Silverado. Open to any suggestions. The goal for this build is the have something nice to cruise in that isn’t going to kill me on gas.

[Scoutboy74]

What transmission and axle gearing do you have? How about the tire size?
I wouldn't think replacing old technology with more old technology would help you accomplish your stated goal. The 392 has better torque than a tired, old SBC to get that heavy brick underway, but I understand they're not easy on fuel, even when tuned to absolute perfection. Have you projected out the estimated costs including man hours it will take to aqcuire and install everything to see roughly how much fuel savings you'd have to realize to cover the up front expenses?
A well tuned 392 in that rig should get 12 mpg on the highway.

[Winchested]

Yep, have you changed the carb or thought about Hamilton Fuel Injection?

You're looking at prob close to $1000-2000 or so to go with an old SBC (mounts, adapter plate etc)

Newer LS can get you into the $3000-5000 range. (mounts, tunes, trans, driveshafts)

I have a friend who did do an LS behind his original 3 on the tree 72 cheyene trans so it can be one cheaper too.

But is your old travelall a daily driver or just a sometimes rig?

[Robert Kenney]

Abelal,

You should consider two things before making any decisions regarding the swap.

1)If you know for sure that the 69 350 or similar vintage SBC is relatively fresh and you will at some point want to put it back to IH powered, it will get you down the road and basically be a simple but not dirt cheap swap. without any major irreversible mods. Electrically you should be able to connect the SBC to the existing wiring without cutting.

2) Are you ready and willing to cut up your Travelall to put an LS in it. The ECU and other wiring on any LS will require a significant amount of hacking up the existing wiring if not a total rewire. It'll never be IH again without the same amount to return to that neighborhood.

Mechanically they both engines are basically the same on the back end. Adapters are available right here in the IHPA store.

That depends on, as SB74 asked, what trans you have.

[mallen]

Originally Posted by Abelal

So I have a travelall with a 392 v8 in it and it’s a gas guzzler. I am in California and gas is very expensive. I want to take the 392 out and keep it stock on the side and drop a Chevy engine in there keeping the same transmission using an adapter plate. My goal is to get at least 15mpg. I have a Chevy 350 from a 69 c10. Is it worth cleaning up an older engine or getting one out of a 2011 Silverado. Open to any suggestions. The goal for this build is the have something nice to cruise in that isn’t going to kill me on gas.

Get out your calculator, or Excel and crunch the numbers. Your engine, properly tuned with a good carb will get 12mpg as another poster mentioned. Its going to cost you something like 2000 dollars to get that SBC in there. Right now gas costs about 29 cents a mile for you at 12mpg and $3.50/gal, which is about what I pay. I'm also in California. At 15mpg you will pay about 23 cents a mile. That's a savings of 6 cents a mile. It will take you 32000 miles to break even.

The big problem is going to be the gearing. The IH engine puts out tons of torque. The SBC needs to rev higher. The gears are set up for an engine that has a 3600 RPM redline and a produces all of its considerable torque down low and your putting in an engine with a much higher redline that products its torque at much higher RPM. Its not going to work well unless you change the gearing for the new engine. That automatic transmission is also going to be an issue. Is it a manual or an automatic transmission? If its an automatic its setup to shift for an engine that has a 3600 RPM redline.

The engine from a 2011 truck is going to require all the electronics to run it. Thats going to run into even more money. Figure 5k. So that would be around 80,000 miles just to break even.