As some of you may remember from my last thread a few months ago, I am planning on putting a hi-performance 351 in my truck.

I went to see the engine builder near my house today. He has a really nice setup going, lots of drag racing pictures, awards for speed records at the local dragway, etc etc.

The guy at the counter was pretty nice, I talked with him for like an hour.

I told him I wanted a 350-ish hp 351 and he said that since it's going in a heavy truck, that I should stroke the 351 to a 406 and that would give me about 400-425 ft-lbs of torque and that it wouldn't be much of a gas mileage decrease over the built 351. The shortblock of that stroked motor would be about 2g. He also said the forged pistons are about $20 more per piston to get them instead of cast. I don't mind the piston slapping sound from cold starts, as long as that doesn't do damage as it does get used in new england winters. He said a non-forged/non-stroked 351 would be about 1500 bucks. These figures are not including assembly. I did really like the shop, no young guys all older guys who I like to see (more experience).

I think 400-425 ft-lbs would be great but a little overboard for the time being. I also know nothing about the 406, anyone have anything to inform me about this stroker (good/bad?). I'm looking at about 350hp and 360-370ft-lbs atleast for now. However, I would also like to be able to somewhat easily get the extra power if for example a couple years from now I decide not to use it as my daily driver and want the extra power. I think I will go with the forged pistons...or should I not? Keep in mine it will be a daily driver and needs to be emissions legal. I am hesitant on the 406 because I still only have an 8.8 and a d44 up front. I eventually will go with a 10.25 out back and a d60 up front...which would easily handle the 406...but I don't think my fairly stock axles will. The other reason I hesitate is the gas mileage. So the only limitations I have for my engine is...

Gas milage (somewhat reasonable 10-12+)
axle strength (can be taken care of w/ new axles later on)
emissions legalness
making sure the EFI system can work with the engine.

I have a MAF kit for the truck right now...I'm not sure if that will run the 406 or even the hi-po 351.

Also, know how nascar uses restrictor plates on their engines to de-tune them for certain tracks....is this able to be done if I slipped a thin plate between the TB and the intake (say for emissions, or to de-tune the motor until my axles are good)? I think that once it becomes my non-daily driver I will want the 400-425 hp, new axles, and not care about gas mileage as much. But I also don't want to build a motor twice...so I have to keep those in mind.

Any thoughts on this?

 

your maf will work but may need a chip burned to get it dialed in just right. did you ask about a 393 instead. either one would work out great if you keep your stock heads but just get them worked over a bit you will stay in the power range you want and then when its not your dd anymore upgrade to some nice aluminum heads and that would put you in the 400 range. you will also need larger injectors as well probably 24- 36's and maf sensor calibrated for this. also a larger fuel pump like a 255. as for your axles i think you will be fine for a little while just because your stock tranny may grown the most for starters. I wish i could stroke my 351 .. someday
late

 

I agree with Kemicalburns, but instead of getting a recal'd MAF, get them to account for larger injectors with the chip.

 

Well I've got the 24#'s injectors, stock MAf conversion kit (also have a 75mm MAF meter calibrated for 24# injectors in the garage), and a BBK 56mm TB in my possession.

So a MAF kit made for a 5.0L engine would run the 351/406? It doesn't need to know it's a different engine, just that the airflow has changed....and you're positive about this (would hate to put the motor in and come to find out it won't run well off it)?

I was thinking about getting some AFR heads, those seem to perform the best. That with maybe an edlebrock truck intake. However, edlebrock has some package deals (heads/headers/intake/cam) which seem pretty nice for the price...so I'm a little torn if I should get an edlebrock power package or buy things separately, (AFR Heads...ford or whoever headers...edlebrock or another intake). The Edlebrock stuff also says it's emissions legal.

I can take care of the fuel pumps, i would probably get the 255's.

Is it easy to get chips burnt for these?

The stock tranny is going for a ZF as a replacement.

 

good tranny replacement. yes the maf you have should run what you got. you may need an adjustable fpr to just in case. and they could burn a chip and get pretty close as long as they have the specs on what your running. I would also hunt down a lightning gt40 intake vs the truck efi intake. reason is it distributes the air better to all cylinders making more power and the runners are long enough to produce good torque.
AFR's are probably the best out of the box. your biggest thing to think about is compression ratio. if you can keep it low you wont have detonation issues. if you can 9.1 would be good 9.5 would be max in my mind. this way you can run regular once in awhile and still be ok. you will want to get an msd box, coil . and remember with going roller cam your dizzy will need a bronze gear..

late

 

From what I've read on Pro-M's website, an adjustable FPR on MAF vehicles is a no-no. They say it messes up the fuel flow curve or something. They also told me when I was inquiring about recalibrating the air meter that engine size does not matter.

 

From the sounds of you are wanting the same type of engine that i have in my pick. I get approximately 350ish hp and about 16mpg and it is smog legal. Anyway my build goes like this, the motor wasa tired out and overheated 351HO, it was bored .03 over and uses flat top forged pistons, it has a mild rv cam (farley close to stock HO specs), the heads is where this motor makes its power, they have chev valves (1.93 and 1.5 something), port matched each side (enlarged as well), 3angle valve job, ported to the max everywhere else along with a polished combustion chamber and exhaust port, then it has a edlebrock performer intake with a carter 650 carb, it has hedman headers (and a 3inch single exhaust with an exhaust cutout), it uses an accel distubor with a built it module. When it was all said and done with the total cost of the motor installed (i installed it myself with my dad) was 3800 with exhaust work included and a new clutch as well.

If i were you, i would stay away from the stroker, cause remember that more cubic inches will mean more fuel, i know that my motor get 16 mpg minimum and thats better than my dads 93 351 and 92 302 f-150s. there are pictures of it in my gallery.

 

mustang is your a 2wd rig?

 

Nope, lifted 4wd (pics in gallery).

I'm still questioning the 406, I think it'll be overkill for me. I think a well built 351 with 350hp and a good low-mid range torque band would be great for it.

As long as it's emissions legal and gets 12-14 mpg, I'm happy. I've gotten a max of 16 mpg all highway on my truck currently. I get as low as 9-10 in the city if I beat it.

 

Well it appears I have to start really getting into setting plans for this swap. My current engine is giving me fits and I am thinking it's a good time to replace it.

I did a quick search of AFR heads, they have a bunch of different versions for my engine. I can only look at the emissions legal ones, but I'm not sure what head I should get. I know that with engine building matching parts together is the best way to make power...so I was leaning to the edlebrock truck intake (don't wish to have the GT-40) which is only like $550. I also obviously was looking at the AFR street legal heads, which ones should I get? The camshaft is something I can figure out when I decide on the heads. It also appears that getting 255 fuel pumps are a challenge for these trucks, but I will do more research on that.

Do I need to have my MAF kit re-calibrated before I put the engine in, or can I put the 75mm meter (calibrated for the 24# injectors) and stock MAF computer on the new engine and run it for awhile?

I've never heard of a 406 until the guy at the shop mentioned it to me....I havn't seen anything about them online either. I therefore assume the 406 is not a popular stroker. I've heard of the 393 before...but do you guys know about these engines, are they any good?

Was my throttlebody restrictor plate a bad idea?

Are forged pistons necessary or recommended in this application? I don't think I'll ever supercharge it and I doubt I'll put it on nitrous.

I wish I could see some dyno graphs of the 351 and 406s, I'd like to see the low end torque comparison but havn't found any.

I appologize in advance for asking so many questions or asking several similar questions. Since this is my first experience with swapping engines, I need to be sure I'm doing it right, I don't want to run into major issues in the middle of the installation or trouble after the install. Having no previous engine experience, I've tried to teach myself as much as I can in the last year or so and am getting a good handle on it, just have a few bits to work out.

 

read here https://www.ford-trucks.com/forums/s...d.php?t=276682 this guy did a 408 build he has everything listed .

as for the maf issue just run the 302 harness and ecu on the motor you will need the mass air flow sensor calibrated to what ever # injectors you get. you may also need a chip burned when done but other then that you would be in good shap

 

Yep, I do have the 75mm MAF meter calibrated to the 24# injectors in the garage, along with the MAF conversion kit and BBK throttle body.

I just looked at that link...all I have to say is wow. Those are some really high numbers in the tq department. 434 ft-lbs at the rear wheels...jesus. That's too much for me atleast for now.

That engine has too much torque and too little horsepower for my preference. 307hp isn't much...I'd rather see 350hp+ and 370ish for torque in the low-mid range RPM.

I want the truck to have good low end power but I don't want it ALL down there like a diesel. I want it to be pretty fast so I want the hp, but i want some low end for off-road/towing.

So now I'm not sure if I should go with the 351, AFR heads, edlebrock intake, roller rockers, etc etc...or if I should go with a 393 and not go all out on the top end of the engine to keep the power down a bit...then I can upgrade later.

Only issue with that is I don't think I'd be able to just put my stock heads on a 393 and expect it to be a pleasurable experience. And I'd rather not spend 500-700 on a port/polish and end up buying better heads later on. UGHH..decisions decisions.

What exactly is a 393, 406, and 408. Is a 393 just a stroked (stock bore) 351?

 

There are many combinations


stoke bore 351

w/t 3.750 stroke - 377
3.85 stroke - 387
4.00 stroke - 402

bored .30

w/t 3.750 stroke - 383
3.85 - 392.8 or 393
4.00 - 409


The number above are the exact result of the forumula to figure it all out.

Basically what your looking at is the common 383/393/408 ci that gets thrown around, just a little more or less depending on the overbore of the cylinder.

Call me crazy but I would stroke that sucker to 408 (402 standard bore 409 4" or what the fella referred to as 406). You can IMO never have too much torque, it may use more fuel to turn the crank but it also takes less effort to move the truck, if you tune it right I wouldn't imagine the mpg suffering as compared to a 351 or .30 351 = 357. I have messed with a couple modifed BB and the mpg was no different than a sb.

My vote go for the afr and 408, and all the other stuff you mentioned. Everyone says run a matched combo to gain this or that, as long as you use the heads intended for the rpm range, you intend to operate the vehicle in and get a cam recommended from a cam company (comp cam ) that complements the combo and ties everything together, you should be good to go. There is always the custom cam option but chances are your gonna end up with what comp cams would recommend anyways.

Good luck....hope it all works out for ya. later


The formula to determine cubic inches

bore X bore X stroke X .7854 X # of cylinders = cubic inches

 

go with the 393, your gonna want good heads for the motor period so spend the money now. a 393 is a 351w bored and stroked. the block is bored .30 over use a .385 crank and 302 pistons and 351w rods. the guy in the link went all out. you dont need to obviously. the 408 is the same except for a .400 crank.
it sounds like your talken scared here hehe. i would go with 393, get good pistons stock rods and steel crank. get everything balanced (most important) . if you want to keep hp down look at edelbrock heads they flow good just not what the AFR's do. you have so many choices and combos. just remember that you do drive a 4x4
wish i was in your shoes
good luck

 

Which AFR head would you recommend? Are the stroked 351's reliable?

The guy at the shop said the same thing about gas mileage, that the 406 would use a little more but you wouldn't need to hit the gas as much.

That guy's 408ci in the bronco forum put out well over 450ft-lbs of torque at the flywheel with AFR heads....i dont know if that is mainly because he setup his truck for all torque or what....but I didn't like how it only had 307 rwhp (safe to assume around 340hp?) but 434 ft-lbs at the wheels.

That stroker with hi-po heads puts out a lot of power...a lot.