Hey everyone,
I'm new to this site and looking for some input. I've got a 78 F100, owned it for a year now. It currently has a 300 straight 6 in it. It's a fantastic truck however it's engine and tranny has become tired and will need replacing. Neither have been worked on in 30 years so what do you expect.
So i'm trying to decide which engine would be the best to swap with. I've got some connections and can get a rebuilt 351 windsor as well as a tranny for $1000. Would this be a good engine for this truck? What other modifications would be necessary? Would a need a new carb and rear end as well?

Or I could just get another straight 6. This route would cost more for the engine and tranny, probably closer to $3000 with no labour. But, I wouldn't have to do any other modifications. My issue with the 6 is that the one I currently have has zero power. Probably because its old and tired but I dont want to put a 6 in and end up with no power. I'm a city driver though, the truck wont be used as a truck very often.. So maybe a 6 would be better for the city?

Anyways, as you can probably tell I dont know awhole lot about vehicles (yet). So any help, hints or tips are appreciated! I know the basics, thats about it. This truck is my learning truck and my long term project.

Kim

 

One more question.
My truck is arm strong steering. I dont mind (usually), it's only an issue when I need to parallel park in small spaces. Is it worth it to switch to power steering or would it be too much of a hassel?

Heres some pics of the truck.. Just for fun

 

Depends on your preference , a 351 w will have plenty of power and if you are not worried about gas prices then go for it , I have a 302 with a 2 bbl carb and plenty of power but gets good gas mileage . If gas were cheaper I would also run a 351 w with a 4bbl , my friend has 1 in his mustang and dynos at 500 hp , mean engine . That is a great price . Good luck and enjoy and welcome .

 

^^That was one of my concerns, gas prices.
That said, its awful on gas now because its so underpowered. I do alot of highway driving and live in a hilly area (i'm LUCKY to hit 50km/hr going up a hill flooring it....). So how much worse on gas would a 351 be if its already awful? Thats my train of thought. I am going back to college in sept though so gas prices are definatly a factor.

Now with the 302, I wouldn't have to worry about switching carbs then. But with the 351 I would need a 4bbl? Those things are quite pricey.

 

The 302 will burn more fuel trying to get the Truck weight moving.

You need torque with HP that's where the 300 is the best choice IMO.

Have you done a compression test on that engine ?

How about oil pressure verification ?

What exhaust is on it ? ...hopefully not a plugged CC

If it was me,I would inspect everything and maybe a $100.00 major tune-up would do wonders ?

 

We've done a major tune up, had everything looked at/changed.
Honestly, not sure what exhaust is on it, all original. Oil pressure and compression has been checked.

Power isn't the only issue. The engine is a pinger. It makes noise, knocks, pings... Runs better with supreme gas but still not great.
We've got provincial emissions testing here as well called aircare. The truck failed aircare it's first time through. Had insanely high Hydrocarbons while idleing but passed while driving. Basically the engine has a bunch of crud in it that settles while idleing (causing awful emissions) but gets burned off while driving.

I'll also add that I dont think it was taken care of when i purchased the vehicle... Had no coolant, desperatly needed spark plugs, oil chage and new filters. So it's been beated up a tad

 

The 300 six is a top notch engine, really hard to beat. Sounds like yours has suffered from too much abuse/neglect. An F100 with a healthy 300 should have plenty of power to get around. You must also consider all the little things that a swap will entail. Carb, distributor, exhaust, fan, fan shroud, alternator bracket. Will the radiator be big enough? I'm not trying to scare you, but many people fail to take everything into account. BTW, nice looking truck!

 

^^Thats exactly why i'm asking, to help understand exactly what should be changed.

So if I switch 300 for 300, dont change size or nothing I wont really have to worry about much else correct? It's got a fairly new distributor in it, carb, alternator, fan, rad, etc are all in good shape. So I dont want to change all that if I dont have to..

 

So what were the results of the compression test.

 

It tested low in a couple of the cylinders. Not 100% positive on the readings as my shop did it when it was tuned up awhile ago. They checked everything and were the ones that broke the news that my engine has issues.

 

You "should" be able to have it rebuilt, for WAY, WAY less than $3000. Personally I would buy a chiltons manual or similar, and pull it out and do it yourself, find a competent machine shop to help you along. Is your tranny an auto, a complete rebuld on that should not run $500 or so. I would get a second opinion, these 300 will go forever, I am going to venture to say you might have a plugged cat, and some carb issues, an Edlebrock 4bbl intake and new carb, 2 or 4 bbl, and a new exhaust might net you some great improvements, I would still have it taken somewhere else and get a second opinion.

 

I wish we knew what the issues with the one in his truck are ?

So far nothing specific.

 

^^Thanks
The $3000 price is from a few local engine shops, $3000 for engine and tranny. I'll definatly keep looking though

The issue with doing it myself is I have no idea where to even start. I dont have the equipment or tools necessary.
I've got a shop that I've been with for awhile. Very honest people, go out of their way to help me. Not to mention the owners and mechanics all have older vehicles and thats really their 'specialty' area. They go out of their way to help me. So I've got them if I need them

 

I dont know the specific issues with the engine, I would like to figure it out to.
Basically, engine lacks power, knocks (especially up hills and accelerating) and it jumps back and forth between gears (only up hill and accelerating).
The engine is also difficult to start in cold and the choke likes to be out about 1/2cm even when warmed up. Tried adjusting the carb, didn't make much difference.
My shop said the engine seems to be tired but hasn't had time to pinpoint what exactly is wrong with it. Either way, it'll need a rebuild

I haven't done awhole lot with the truck yet, as I said I'm still learning. So far it's had a full tune up, new hoses (upper rad hose), new alternator and a fan belt.

 

Did they check the vacuum advance on the dist for a seized or torn diaphragm ?
Vacuum leaks ?

There are so many things that could cause this and we haven't heard anything specific about the actual condition of the engine.

Did they not write down the results of the compression test ?


By the way, I am tired right now myself but I know why