Hi,
I have a 1976 F250 Ranger XLT 4x4 with a stock 360 (although it has dual exhaust), an NP435, and an NP205, 410 gears, stock tires.

I live in the mountains traveling anywhere from 6 - 14000 feet. I have only been at 11K so far, but the truck runs good there. I don't hot rod much and generally stay below 60 mph. I have been getting 10ish mpg on good tanks. I have read that won't change much or may only go down if I add power. I tow very occasionally and relatively light loads (<5,000 lbs). I do like to 4 wheel in the mountains a lot. In face that is really the purpose of my transportation these days, to get out in the mountains, and within reason, I expect it to keep up with my driving skills off road, which I would consider advanced.

This is what I am more interested in for this thread. Example Road: East Bound Rabbit Ears pass from Steamboat Springs. Approximately a 7% grade for about 12 miles. Speed limit 55 mph. 600 lbs of gear, people, and dog.

Now, I am used to a hopped up 7.3 PS and a deleted 6.7 Cummins. I think this might be flawing my expectations. Both trucks would run up the pass loaded with plenty of power to spare. I can obviously compare factory power specifications which when it comes to torque there is no comparison.

The question: should my setup have trouble holding even 50 mph of the pass very lightly loaded? I have to bury the pedal to maintain speed in 4th, and the temp gauge shows between the M and P, sometimes on the P completely (Scientific, I know) I haven't tried towing with it yet, but I am a little scared to. I also will have to for an upcoming move. I am also interested to know what other things I can do to increase power but I don't necessarily want to trade mileage. I am mostly looking to be able to cross mountain passes with some power to spare.

One more caveat, I haven't decided how much I want to put into this 360. I am a cummins fan, and have my eye on a 4bt in the stock drive train with an overdrive unit as a unique, efficient, torquey setup. But that could be out years potentially, so I would like to get the truck a little more mountain capable in the interim. Speed isn't real interesting to me as far as top end, but grunt make me happy!

A picture of the pass.



Thanks!

 

At higher elevation, a turbo diesel will always rule. The turbo helps pack in more air, when it starts getting thin.....

A 360 is never going to have the grunt you want. It wasn't designed to have grunt, and in that respect, they succeeded remarkably.

Building the 360 into a 390, adding some decent comp ratio pistons and a mild cam, will give you more of what you are looking for. Best of all, the MPG won't go down much, most of the time. With a lot more grunt to offer, you don't have to stand on the go pedal anywhere near as hard to do the same amount of work.

 

I'll research those parts. So off hand how much do you think that option costs?

 

Lloyd, I have never been out there so I can't advise. A F250 4wd with 410 rears behind a 360 should still pull. If you are getting 10 mpgs with that heavy truck you better keep smiling.

Back then they were experimenting with emissions, some things went good some not. As Rogue alluded to, rebuilding it with more compression, a rv cam, headers will increase it's potential.

After saying that, the Cummings with OD would make a lot of seance for the power and added fuel mpgs, since there is no OD available for the FE that isn't very costly.

It comes down to how much jingle is in your jeans.


John

 

Pistons/rods/crank are all that is needed to convert from 360 to 390. If the bores are ok, and the current pistons are ok, you can reuse them with the 390 rods/crank. 360 pistons are older car 390 pistons, chosen by ford to use in the 360 so they would stop over .100 down from the top, resulting in mid 8's for comp ratio. Putting them on 390 crank/rods will net you mid 9's -low 10's CR, depending on how much head work is done. More than enough to wake up the power when combined with a mild-moderate cam.

If the block and heads don't need much (or any) machine work, you could do this for $500-750. If these items need plenty of machine work, and you wanted to go with the best of everything, you could spend $2500 or more.

I am doing a Cummins swap, and I'm about $2500 into it so far. Still have $500-1000 worth of stuff to buy before it's finished. However, I got a killer deal on the engine, and pretty decent deal on the trans. $1750 for both (not from the same source). I've seen people pay that much, or more, for just one of these particular items.
I got a 6BT with 120K on the clock. The cheapest 4BT I have found, is $2500. Had a 4BT been available for the same, or less than I got the 6BT at, I likely would have gone that route. It's not that uncommon to get 50% more engine, for 50% less money.

 

Not very much right now.... Thanks for the info!

This all makes sense. So it might be half again as much if not double to do the Cummins swap it seems?

Here's a question though. My understanding is that to do a 6BT, you need to basically redesign the front to the handle the weight, as a 6BT is around double what a 360 ways. I have had trouble quantifying whether or not that cost outweighs the difference in the 4bt, not to mention the labor and time finding a new axle, trimming the cross member, new springs, etc... Another thing I have noticed is that all of my previous diesels have been quad or extended cab along with the massive engine and this truck seems to be almost half the weight, which I like for some of the off roading applications I get the truck into. Because I do not currently own, or really plan to tow anything that would exceed 10,000 lbs... and to make that statement more realistic, 5,000 lbs... I think a 6 bt would be over kill.

However, the swap would be at least a year down the road if not longer. So in the interim, I am thinking I would like to add some power to help with these passes. I do already have the dual exhaust, but stock headers. Would that make a big difference? Also, what kind of air cleaner would be good bang for the buck?

Last question, if I abandoned my love of diesels and decided to make this a 390 etc. Does anyone turbo or supercharge these trucks?

 

I had a 75 f-250 4x4 with a 360 & 4.10 gears,it pulled fine with lots of low end grunt,then later put a 3500lb camper in the back and a 3000k boat behind,then it was a little slow on hills.then upgraded to 390 with around mid 9 C-ratio then I could pull most any mountain pass in 4th, 55mph or faster. mpg was about the same 10 pulling hard,12 empty. forgot to mention, 360 or 390 never even tried to run hot under any load or any weather,ive pulled mountain passes with load mentioned over 100 degrees no problem,as well as idling in on hot summer days on the 4x4 trails with stock cooling sytem

 

I thought I had a 360, turned out to be a 390. Don't be surprised if someone swapped out the engine at some point in time.

Check your current cranking compression. Hopefully, it is over 120. If the engine is just tired, keep an eye out for a complete 390.

The only other recommendation I'll make is to find a 4V intake and carb. Ford used a Holley 600 CFM, and it worked well in the application. You can usually find the iron intakes pretty cheap. Look for a big letter S or T cast in the runner.

 

Thanks everyone for the responses. I'll do some more research based on all the info you gave me.