Hey guys, I am really new to FTE and this is only my third post on here. Anyway, the engine in my 1973 f100 is very tired, to say the least. It has trouble starting sometimes, has a dead spot in the throttle, and leaks from the rear main. I had it reviewed by a mechanic and he said that it definitely needs a rebuild. Not to mention, it is super, super weak. So, I was reviewing my options and thought I could use some help from some experts. My truck has a post emissions 360 v8, 4 barrel carb, and headers. That's all I know about the engine pretty much. Anyway, here are my options I have considered so far:
1. Get this block machined and rebuild it as it is.
2. get block machined and rebuild as 390
3. buy 390 long block and attach all of the exterior parts I have.
I really like the third option because it will get me a lot more power because I can buy a 60s long block(pre emissions).
I am not an expert and I've never rebuilt an engine, but I will be doing this next fall when I have access to a garage at my shop class in school. They have all of the tools I would need, and the teacher can help me out. I will be working all summer to afford this, and my budget will be around 3 grand. Also, I would like to get above 300 hp and at least 400 foot pounds of torque. I know this is a lot but if any of you guys can give me any advice I'd really appreciate it

 

Has a compression test been done by you or the mechanic? I'm not sure what your experience level is but getting a compression tester and doing it yourself isn't too complex or pricey. A compression test is usually the easiest way to determine the general health of the motor imo.

Do you know the timing of the motor? Has it always been this way for you?

I only ask because with just the above it may not need a rebuild just some tuning and much smaller scale fixes. I only mention it as you might be able to get to a state where you are not unhappy with the motor.

 

Read posts 8 and 24.

https://www.ford-trucks.com/forums/1...m-pistons.html

For the 300/400 numbers you are after, you will get there with the 9.5 compression setup, a mild cam, a good intake and 4bbl and headers. At least shorty if not long tube.

This assumes good engine building practices and clearances etc etc.

There are a lot of ways to build FE engines. Pickup spec motors have sunken pistons and low compression. You can improve them, but you leave a lot of potential behind with the sunken pistons.

 

Please ignore, accidently posted something twice.

 

Thanks, I will look into doing a compression test. But, I do know it definitely has to be rebuilt because apparently the crank bearings are worn. He says I can drive it for the next year or two, but I should really rebuild it. It runs fine enough that I can drive it for the summer, but I would just like to have it start easier, idle better, and perform better too. It is incredibly slow. Not to mention mileage and reliability.

 

Is this with a 360 or a 390? Post or pre emissions? ETC. I also saw on some other threads something about keeping the 360 pistons to up the compression. Is this something worth doing? I already have an edelbrock intake manifold, quick fuel 650 cfm carb, and headers.

 

A 390. There is no inexpensive fix for the sunken piston in a 360.

Do you have emissions testing and inspection to worry about?

 

I'm going to register it as a classic so no. Also, how do I up compression?

 

Gotcha. I'd recommend this book as good to have as you research this (Obviously keep using the forums. But if you're anything like me having a book to pour over can help me wrap my brain around different info). Link is for amazon. Just using it as a link to the book feel free to source it elsewhere.


I used it when I built my 390. read it extensively beforehand and during.

 

I'll check it out, thanks.

 

Regarding compression, see post 3.

 

Alright awesome, so what I'm getting from this is that I should keep the 360 pistons (which are car pistons, right?), get 390 crank and rods, and buy a mild cam? I already have a 4bbl carb and long tube headers. This would put me at a 9.5 compression ratio, and I believe put me at my spec goal.

 

You should not count on keeping the 360 pistons. They are used, worn and would be a good way to turn your new motor into a knocking oil burner.

Yes, 360 pistons on top of short rods and a 390 crank give you the same setup used by late '60s car 390s. Slight dish was advertised to be 9.5. Flat top 10.5.

You need measurements from your engine and combustion chambers to be able to figure out what CR you will end up with.

 

Alright got it. I will buy either some 360 pistons or some car 390 pistons, 390 crank and rods, a mild cam, and rebuild my engine using those parts. Thank you so much for your help.

 

The book listed above is a good idea, and review a bunch of threads here as well. Once you get the parts figured out, being aware of assembly issues and tricks is important.

If you can swing it, a roller cam will eliminate the wiped out cam problems people have been having with flat tappets and current oils.

For your extra money you pick up a few HP to boot.