I have a 1979 F150 and I'm trying to figure some stuff out. The truck has the 300 I6 in it but she's not wanting to run reliably. She started up when I bought her, but ever since it's been off and on. We've tried adjusting the distributor, the carb timing, and new sparkplugs and wires. The previous owner had done "upgrades" to the truck, like a new cam and a 4 barrel carb.

Now for my question. Would it be better to pull the engine replace it or restore it to stock? I have an old 351w I pulled out of an 80's Bronco that I'm planning on rebuilding over the summer that I've tossed around the idea of dropping in the truck.

My plans with the truck are to use it as a daily/medium trail rig. I plan on removing the body lift, putting on a 4in lift, running 36" tires, redoing the entire front end, and making her look a little bit prettier.



*Edit to add extra details

 

Even with your extra details there aren’t enough details.

Have you done a compression test and/or leakdown? What were those results? Did you have a vacuum gauge hooked up when adjusting the mixture and timing? If so, what were you seeing? Did you use a timing light? If so, what is your base timing with the vacuum advance hose disconnected? Checked for good grounds? Check for good fuel flow?

Don’t fall into the trap of thinking that throwing another engine at the problem is going to fix it. If the fundamentals aren’t there you’re going to be holding the same **** sandwich with different condiments.

 

I apologize, I don't really have the tools to do any of that. This is my first real project outside of replacing old parts. Looks like I'm in for a hell of a summer 😅

 

I've been working on a 1984 F250 with a 300. I recommend you making it right, you will be amazed how easy the 300 is to work on.

 

FINALLY !! Another Alaska person on the FTE with a 300 i6. My truck has the same issues, it is a mix of better fuel and adjusting the fuel system. Right now, mine will not want to start unless primed with fuel dripped into the intake. Then it starts up and runs good, until it idles and then has some issues, mine idles really low, but octane booster seems to help. I have some pretty bad fuel as it is the color of dirt. Best thing is convert it to stock and go from there. You could have a vacuum issue with something not working. You should check all of your fuel lines, and see if you happen to have a hole in the tank. I added an auxillary high output pump that draws the fuel from the tank faster than the mechanical fuel pump and it will help it. 300 i6's are really fun once you get it to have some pep, with a cam, boring, efi, ect. I think your truck is absolutely bad***, but if you want it to have some really good power other than just low end, better swap in either a 400 or 460, might help you out a bit.



I have a 1978 f250 with a 300 i6 and a 4spd, it has some upgrades like a fresh rebuild with all pistons, rings, cam ect, however I need an intake and if you want to sell yours let me know. P.S. If you don't want your winch or bumper I think they would look cool on one of my rigs. My 2 cents
Coming from a broke teenager halfway between Tok and Glennallen

 

Takes about 3 to 5 hours to pull the motor. The real issue is the wiring.