Hey fellow Ford fans, my name is Kell.
I have a 1986 F250 2wd that has a 351w that is carbureted, and has the auto transmission.

I dont know much about this truck, but it currently doesnt run. I want to pull the motor and rebuild it.

I am new to building engines and I have read a lot of great information on this site, but want to make sure that I order the right parts/best parts for my needs. So any help/ideas would be appreciated. Links to informative articles/videos/build threads are welcome!

Im looking to get into the 375-400hp range. Its a 2wd truck, so Im only running 33s for tires.

1)I want to bore it .030" over. Which rotating assembly/guts are good? Which heads-gt40s, aftermarket, etc? How can I figure out which parts work together so I don't have to ask you fine folks? I would like to be self sufficient as much as possible. Im not very well at searching and navigating the forums though lol.

2) I want to swap the auto trans for a 5 speed manual. Is there a good tutorial, and which transmission would work for my truck? What donor vehicles/years do they come out of?

3) whats a good aftermarket radiator to run?

Thanks in advance, I'm trying to make this a fun learning experience..

-Kell

 

It is good to get ideas from people but they need to know what the truck will be used for and the big one how much $$$$ you can throw at it.
What parts do you have or you have nothing?

The other thing is talk to machine shops or others that have use that shop for motor machine work.
That shop will need to see the motor before they can give any information on what it will need.

The crank may not need any work but if you want to make power it may need to be off set ground for more stroke. That leads to different rods & pistons, read $$$$.

it is nice to say I want 400 HP but you will need to dig deep in to the pockets. Just look into crate motors to see what they run and add more to that.

So with all that why do you think it needs a rebuild if you have not heard it run or checked the shape of the motor out first?
Dave - - - -

 

375-400HP pretty much means aftermarket heads. It can be done with factory heads with some work and careful cam selection. But will be far easier to achieve with aftermarket heads and allow for a larger selection of cams. Shot for a 9-9.5:1 Compression ratio. There is a package available that will drop you right in the range you want to be in.
https://www.cjponyparts.com/edelbroc...51w/p/EDL2092/

 

I would not get crazy with the duration and overlap unless you just gotta have the lopey sound.

 

$2700 just for the top end kit you still need to deal with the bottom end lets call that for S&G another $5000, machine work is not cheap and you have parts too, so that's $7700 right there.

You don't know if that can will even work for what you want to use the truck for. It may work in a higher RPM range than the truck is geared for, If you have an auto may need a different stall also.
With 33" tires you better have a 4.10 gear and even then it may be a dog off the line.
For a truck you want to build it for TQ not HP and to be down low like off idle to 3500 RPM max.

That is just my .02
Dave ----

 

Thanks for all of your replies. At this point, I have nothing in terms of parts. Im going to pull the notor this weekend. I was told from the previous owner that it overheated and water got in the oil. I received the truck with no oil in the block, so i am unsure if this was true. The previous owner said he installed a new water pump and probably put the bolts back wrong and thought this was how water got into the oil. Is this even possible? So anyways it overheated, and probably needs new heads so I figured a rebuild would be more worth my time.

I am going to use the truck to pull a 14 foot long double axle flat deck trailer with lumber amd other building materials, so I need the torque more than anything. However, I want my power in the lower rpm range anyways. Preferably below 4500rpm.

I have no new parts, yet. As for machine work, my uncle runs an engine machine shop, but its a few hours away and unless I stop in to pick his brain, i have no other way to contact him directly.

As far as money is concerned, I have money that I have been saving for this build, so I'm not concerned about total cost. And my machine work will be next to free. I want to 5 speed manual swap the trans as well.

I have 4.10 gearing in it. 33s with this gearing is fine. Hell my toyota with 4.10 gearing pushes 35s no problem with a 4 cylinder engine in it.

I just was curious what parts could make 375-400hp possible with this engine. I already planned on the purchase of new heads, just didnt know which heads were ideal. And since money isnt an issue, wanted some opinions. Sorry that I didn't clarify that, and thanks again everybody for your time and input. Cheers
-Kell

 

Have you given any thought od maybe a 460?
I know some have mated a ZF5 to a 460 (do a search) but think this would be a lot of work as no 5sp was used with one and when they started matting a stick trany the 460 balance changed but the 460 gets you more TQ and HP to start and you can get a C6 to mate to the 460.

If looking for over drive you have Gear Vender OD unit that bolts to the C6.
If you went with a T18 or T19 you can go with either GV OD again bolts to the rear or Advance Adaptors Range Splitter between bell housing & trany.

Lets see what others have to say but don't get stuck on the HP number as it is TQ that get the job done.
Dave ----

 

With the HP you want to make the easiest solution is use the aftermarket heads. Plus you will get advantage of being able to run a higher compression ratio on the same gasoline. Higher compression=more power higher efficiency and better low end torque.

Cam selection is what will determine where your power is. The cam in the kit is a mid range unit likely not ideal for what you want.

Factory heads D0OE or GT 40's can be used the GT 40's will make the 375HP but will struggle to get to 400HP with out major work, and cam selection will be critical.... of the 2 the D0OE's are the better choice but they will require the press in studs to be removed and threaded studs and guide plates used.
If cost is not a big issue then a set of aftermarket aluminum heads is the way to go. They will allow for more cam options to meet your HP goals.

The guys at car craft did a budget 400HP 351W build several years ago and managed 391 hp at 5,900 rpm and 405 lb-ft at 4,300 rpm with GT40 heads that they had fitted with larger valves. As you can see they had to spin it to get those numbers.

If you shoot for a more reasonable 350-375HP you can use a set of bog stock GT40 heads still make 400 FT lbs of torque and have good bottom end.

 

Yes, it's very possible, especially if he replaced the bolts. From my vast 351W experience (1 and not counting!), the blind bolt holes in the block tend to collect coolant, which turns to solid crud. If you don't break out the crud and clean the threads with a tap, the bolts will bottom out when reinstalled. Under the best scenario, if the threads aren't cleaned, there will be zero clearance at the tip of the bolt. Assuming the bolts scrape off a little crud during installation, that debris gets pushed ahead and prevents the bolt heads from seating.

New bolts? If even a smidge longer than original, you've got the same situation. In either case, the bolts FEEL like they're torqued down just fine. However, they aren't applying adequate clamping force because they are bottomed out. The end result is a leak.

​My poor, tired 351W used up 8 of its 9 lives almost three years ago. I was convinced it was a goner, but I was less correct than usual. Here's my sordid tale, with an All-American warm and fuzzy ending like something on the Hallmark Channel:

https://www.ford-trucks.com/forums/1...-a-bullet.html


Said engine has since logged many thousand hard-working miles with nary a complaint. Don't be too quick to write off your engine but perhaps investigate if it can be nursed back to life. No idea if your existing engine capabilities would meet your needs, though. If it's any help, my '84 351W 2 bbl has performed admirably hauling a camper (fully loaded to 8600 GVW) while also towing a Jeep.

 

I've been very pleased with #220452 from Radiator Express in my '84 F250:

https://www.radiatorexpress.com/Prod...220452/1123838

More details:

https://www.ford-trucks.com/forums/1...lant-leak.html

 

FuzzFace2- A 460 is very doable, but I kind of want to keep it small block with the stock 351w. I made an error when I said I wanted to 5-speed manual swap it, what manual trans came with the '86 F250 with a 351w? Im assuming Im looking for a 4speed manual trans? Which transmissions will work for me, from which year vehicles? The options that you listed for OD with the C6 is tempting though, hmmmm.....

matthewq4b- Sounds like my best solution would be bone-stock GT40 heads. 400 FT lbs of Torque sounds adequate, and I am not too hung up on the HP number. 350-375hp would do. Would the stock GT40 heads give me the 400-ish FT lbs of Torque with stock cam or what cam would I be after? Do I buy the GT40 heads used, and if so, which years of which donor vehicles have the ones I need?? Thanks for any input.

kr98664- It is very likely that the previous owner installed the water pump bolts in the wrong locations. I know they were stock bolts, just installed incorrectly. So that must have resulted in the coolant in the cylinders. Previous owner stated driving the truck for about an hour after he put on a new water pump before it ocerheated and he then had it towed home. Knowing the above information, would it be safe to assume that the coolant in the cylinders trashed the cylinder walls/pistons, is it safe to assume the bottom end could be garbage or in need of a rebuild?

Which new water pump is recommended, and is there a water pump bolt kit sold anywhere for my '86 F250 with the 351w?? Part #s or websites/links would be greatly appreciated.

Is there a diagram anywhere out there showing which length/diameter bolt goes where when installing a water pump on a '86 351w?? Knowing that they are in the wrong locations now, I am not going to know where they go when I go to do it again. I would want to tap the holes to clean the threads as mentioned and would prefer to install brand new bolts (if at all possible).
Very inspiring story kr98664, and if you pulled a loaded camper that weighed that much- then I'm safe to say that my 351w smallblock should be adequate.
Thanks for the radiator suggestion, is your '84 F250 an auto or manual trans? It does make a difference when selecting a radiator, is that a correct statement?

Thanks to everybody for your time, consideration, and for putting up with my questions. Ive only ever done minor services like clutches, gaskets, cv axles/drivelines, struts, etc. Never messed with internal components of an engine. Thanks again for hanging in there everybody and bearing with me. Lol its appreciated more than I can express. Cheers,
-Kell

 

GT 40 heads were used on 93-95 Mustang Cobra's and Mid 94 to mid 97 Mountaineers and Explorers the Lightning in this era also used them.. So yes you need to buy them used avoid the GT 40P heads they are a bit better head but the spark plug angle is revised (more straight) and they can cause clearance issues with many headers.

No you are not going to make that HP with the stock cam. You will need a 4BBL intake and carb And yes those heads will get you in that range.

Cory (Rembrandt) just did a similar build, but on a 302 he used the GT40 heads 4 BBL intake Holley carb, headers, running a 9.0ish:1 compression ratio and ended up with 297HP at 5400 RPM, and 334 FT lbs at 3100 RPM when the engine was dyno'd . The cam he used is below
31-234-3 - Xtreme Energy? Hydraulic Flat Tappet Camshafts
This is a pretty mild cam.

I would opt for either of these cams below for your build this is a step up and a bit from what Rembrandt used, you will need to step up to meet your goals. Either of these will get you in the ballpark of 400 FT lbs and 350ish+ HP with a 4BBL carb intake and headers. And still maintain good bottom end torque and idle
35-238-3 - Xtreme Energy? Hydraulic Flat Tappet Camshafts
35-239-3 - Xtreme 4 x 4? Hydraulic Flat Tappet Camshafts

As for a trans, the ZF 5 speed from a later 351W truck would be your best and easiest swap. Cory swapped in the Mazda 5 speed trans, if I recall correctly the swap will be similar if not near identical for the ZF.

Water pump bolts
https://www.cjponyparts.com/water-pu...993/p/WPB8501/

Rembrants build thread
https://www.ford-trucks.com/forums/1...n-removed.html

 

Going out on a limb here, you're a glass half-empty kind of guy? I guess it's all personal preference, but I'd be willing to gamble your time and money on a new water pump and see what happens. Pressure test the cooling system. Check for combustion gasses in the cooling system. (I can walk you through the process if needed). Check the oil pressure. If all three check good, I'd be tempted to try driving the truck for a while and just see what happens. Or maybe you've got money burning a hole in your pocket and are just itching to do a full rebuild, and not having to worry about reliability. Your call, but I'm cheap and would not be surprised if your engine will be just fine once you get the water pump squared away.


To make the job easier, without having to pull the timing cover, get an extension tap:

Link to Extension Taps

Sorry I don't remember the thread size you'll need.

You'll also find it much easier to work at the front of the engine if you pull the radiator. You'll already have drained the coolant, so it's only 4 bolts to remove the upper brackets and you can lift the radiator right up and out.

My truck has the T-18 4-speed, but most replacement radiators include a transmission oil cooler whether needed or not. Mine did, I just plugged the holes.

 

Sorry everybody for not getting on for a while- stuff has been hectic lately. I delayed yanking the motor, but I definitely will soon.

matthewq4b- Thanks for clarifying the heads, that helps a lot!! And it looks like I need to source a ZF 5Speed to swap in. Thanks for clearing that up. The link to the water pump bolts saved me a lot of hassle- you rock!

kr98664- How do I check for combustion gases in the cooling system? Whats the process for checking oil pressure? Thanks for the link to the extension taps- thats a handy bit of information and it is much appreciated! Do you enjoy the T-18 4speed trans??

I forgot to mention- the truck sat for about a year with no spark plugs in it at all. What should I do about this? If I can have any helpful insight as to what to do about the surface rust that resulted from this in the spark plug holes, that would be awesome! If I can take care of the rust issue,the water pump/bolt issue, and the cooling system and oil pressure checks out- I will probably drive the truck a little bit just to see how the engine performs and note any other problems that I may notice before yanking the engine. Regardless- the engine will come out and be built in the near future.

Thank you everybody for your time and consideration on my topics- knowledge is power and I enjoy learning from the community.
Cheers,
-Kell

 

If you're going to spend money on GT40 heads and then wind up paying money for guide work and a valve job, you may as well buy the Edelbrock E street heads. I put them on my 351W a couple years back and it woke that engine right up coming from the D8OE smog heads or whatever they were. MPG picked up, lots more power, runs smoother, higher compression. My 351W is relatively mild with just a small Comp XE250H cam, those E street heads, Weiand stealth intake and a 600 CFM carb as well as long tube headers and a nice exhaust system. It has plenty of power to do anything that truck can handle weight wise. Just my thoughts on the heads. I wouldn't waste my money and time sourcing used heads to rebuild/use.