331, 347, or 408?

[Broncobowsher]

If you want to get into rod angles, I like long rods.
The 289 was a better running engine than the 302. The 302 should be a better engine with more cubes and longer stroke, but I have always felt the 289 was just a better running engine. I know others that like the 289 but can't say why. This is in stock 2V flavors all they way into the high compression performance stuff.

Part of the 351W development was to make it a long rod motor. Hence the raised deck.
My last 351 (built just before all the affordable stroker kits came out) was built stock stroke but long rod. That was one happy engine.
Get into high end, make all the parts what works best and not to a price point or package constraints and you will find long rods are king. Short rods are a manufacturing constraint of trying to package a long stroke engine in too compact of a package.

Talk with real engine builders (not just assemblers of a box of parts but people who actually make engines out of big blocks of metal, a lathe, and a mill), people who only use an existing engine due to class constraints, long rods are the preferred design. I know a real good engine builder who makes stuff for Bonneville, late 30's straight 6 Jimmy engines that get 4 to 7 main bearing conversions (bolt the crank into the girdle then bolt the girdle into the block). Just to stay in the prewar engine class. Sorked for Gurney in the 60's. Factory Porsche race team in the 70s and 80s. Got plenty of lecture on why a 2:1 rod ratio is really good.

Or maybe the coworker who worked for the best damn garage in town (Smokey Yunick) that I just got a late 80's GTP wheel from (going to be an end table in the living room as soon as I clean it up and get a glass lid made for it).

I've been around too many really good people to ignore there advise. I'll do long rods as much as I can. And a 351W block gives so much more room to run a longer rod.

 

[HoosierDaddy]

I've been around too many really good people to ignore there advise. I'll do long rods as much as I can. And a 351W block gives so much more room to run a longer rod.

100% spot on Bowsher.
But:
At some point, each of us has to decide what will be good enough.
You're talking about theory from one off engines machined from a solid ingot , built to run Bonneville.
I'm talking about stroking a 302 and running the Blue Ridge Parkway.
There is always a "better".
I've run into the same issue with building a new energy efficient house, at some point you have to stick your head out of the rabbit hole of information and say,"this is good enough" or "I'm drawing the line here". They have even titled it now. A PGH, a pretty good house.
.

I think I have built a PGE. A Pretty Good Engine.
Once I learned that many of the newer motors are running more severe rod angles/ratios than a 347, and the same was true about the 383 (the dream motor I've always wanted to build since I was in my teens), and they all have been lasting pretty damn well, I was done.
I was tired of circling the drain looking for what is "best". Certainly, somebody whose mission in life is to build world class one off race engines will disagree.

I am willing to try it, many others have gone before me and are quite happy.
I drew the line. It's my line, you have yours, and I'm good with it, hell , I actually agree with it .... and I essentially typed all of this for the original poster.
That's the funny part, he has to dig through all of this and decide where his line will be. Any of those motors he listed will work and be stronger than what he has.
Now , which one is best?
hahaha! (insert evil laugh)
Enjoy the ride!

 

[Broncobowsher]

My build standards (budget) is often less then my preferred engineering standards as well.
But the no replacement for displacement is still a big factor. With as easy as a 351W fits into a Bronco I just don't see the value in doing a stroked small engine when the 351 already starts off with more displacement and gives ample opportunity to go even larger. It's not like packaging is an issue (as it was when doing my V8 Ranger). The 351 fits so well that I have had to do a double take at times to see if the engine was a 302 or a 351. There are good reasons Ford didn't just make a stroker 302 and went through all the R&D to make the 351W. The raised deck height, larger head bolts, larger main bearing bolts, larger bearings. Come to think of it, I don't hear about thrust bearing failures on the 351 as I do with the 302.

Pick a foundation and build off of it. the 351W foundation has so much more to offer.

 

[kb6677]

HoosierD. My tranny will be a nv3550, but I,d also consider a 4sp auto overdrive also. (700r4 or 4r70 etc etc)
Final gearing will be decided after it runs, but with 33's and OD , even 4:56's are acceptable according to the charts.

After the detailed post on your engine build/specs on your 347, are you not concerned about the advertised limit of the magic "400hp" with the nv3550??. It would seem like a person who spent all the time and money on such a 347 build, they would step up to the NV 4500 to make sure the drivetrain would handle the power produced - if you want to stay with a gear banger OD tranny?
Just curious

 

[bax]

I have driven the 3550 in a bronco with a 347. I can tell you right now. It's a blast to drive. But with me driving, there is no way the 3550 would live behind it. 35'' tires 4.56 gears, foot on the floor speed shifting. I had to stop driving it. I just knew the next shift was going to be its last. My point the 347 is fully capable of breaking that trans. I guess it depends on how you drive but the 3550 would not be my trans of choice for anything with good power.

 

[nvrstuk]

Fun to read this and other "best engine threads"... like many of us here, I've run what seems like a ridiculous number of engine/trans combinations...

My preference for street:

HP289 w/toploader 4 speed... hoot to bang thru the gears but couldn't go slow off road and this was waaaay before any doublers were out there and Atlas t-cases didn't show up for another 10 yrs + . With corrected odometer we consistently got 17-18 mpg carb'd. No efi back in those days...be great now. Grenaded 28 spline axles on a regular basis like they were spaghetti...


My preference for being able to drive up to a 1,000 miles to go wheeling (not a trail only rig) in severe off road situations:

418 w/4r70/KluneV/Atlas 4.3 You can manually bang thru the gears on the street, snow, sand or cruising the trail. 418 gives you enough torque to rotate the tires when in deep snow and soft sand. Drivetrain handles the torque when built.



Guess I'm saying you can ALWAYS back off the throttle when you don't need 500+lbs of torque but you can't wish you had it by pushing the skinny pedal thru the floor when you can't follow your buddy up the hill... : )

Your choice, we've all got opinions on what works for us. Good luck have fun but the 351W block bolts in with your 2" BL and is much, much stronger than the 5.0 block hands down.

PS...the 347 is more popular because it fits under the hood for the 'Stang crowd...

 

[Mtgrizzlymn]

I wouldn't mind that 347 looks like a good combo for myself

 

[LowCountryEB]

Great points....anyone else?

 

[HoosierDaddy]

HoosierD.

After the detailed post on your engine build/specs on your 347, are you not concerned about the advertised limit of the magic "400hp" with the nv3550??. It would seem like a person who spent all the time and money on such a 347 build, they would step up to the NV 4500 to make sure the drivetrain would handle the power produced - if you want to stay with a gear banger OD tranny?
Just curious

Sorry , been gone for a bit.
LOL, Due to all the praise regarding how the 3550 shifts, drives , feels , etc etc , I really wanted that tranny. So a 408 was out for sure!
I also wanted a high torque motor to spin that tranny , and I have never been a fan of the 302 in trucks. Hate it actually.
The 3550 , as I recall , had pretty decent power ratings, so I knew I couldn't go crazy on the motor, maybe I did, a little.

As far as the 4500's or 435's, I already had the 435 in that Bronco behind a decent 302. Outstanding off road, HATED it on the street. Either way, shifting like a dump truck would not be acceptable on this particular Bronco.
The 435 is in my offroad beater now.

 

[englewoodcowboy]

As others have stated, my original plan was to go with the NV3550 and I too was not a big fan of a stock 302 in a truck from past experience. I decided long ago I would build a stroker and was actually looking at doing the 331 kit but with stock dia. pistons to have a 327. When I was going along, Nick talked me into going for the 347 since the price was virtually the same with the exception of having it bored .030 over but I was also gambling that my donor motor had clean straight bores that didn't need much. Turns out it needed a bore and I know I will be glad I did go up to the 347. I also had an AOD laying around and looked at TQ ad HP numbers and decided that while rowing gears is fun and sporty, they do get old when traveling and I plan on doing lots of that with my bronco so I custom built my AOD to handle 500hp and know it should live very happy behind my 347. Projected numbers on my engine is 450tq 400hp reaching max tq at 3000rpm and Max hp at 5000 rpm.

 

[Cortez]

This is a great thread...I have a stock 351w with np435 and 35s, and have always wanted to step up to the 408 just because it's dang sexy. But with all the input here I am seeing that it's more about balancing the whole drive train for how you want to drive.

 

[englewoodcowboy]

This is a great thread...I have a stock 351w with np435 and 35s, and have always wanted to step up to the 408 just because it's dang sexy. But with all the input here I am seeing that it's more about balancing the whole drive train for how you want to drive.

That is exactly it to a T. You have to be honest with yourself and be very realistic about how you will spend the majority of your time using it. If you build it to be very happy with 80% of your driving or more then you will be 100% happy with your rig. I have gone back and forth with mine since buying it in 2010 and finally starting the resto 2 years ago. 1 thing I wanted was to have a nice sound and have plenty of power, you could look at a 408 etc but then at that time as others have stated, you will exceed the stock drive train and at some point you will be working on it more to make it reliable... It is easy to want more but finding that balance where things will live happily with your intended use... But hey, it's only money!

 

[DirtDonk]

Back with some more info. Here are the Dyno results for LowCountry's engine.
He can fill in any details.



That using rear wheel rollers LowCountry?

Paul

 

[LowCountryEB]

Yep, rear wheel rollers. And thanks for posting Paul!

 

[Faster Eddie]

Here are some dyno results:

306
View attachment 389387
331
View attachment 389388
347
View attachment 389389
408
View attachment 389390

The 347 looks like a real winner, but I hate not being able to see below 3000 rpm.

Paul

Those numbers are at the flywheel. Put it in your truck and run it on a dyno, and those HP & TQ numbers are lower due to drivetrain loss.

 

[LowCountryEB]

What is a reasonable amount of difference? 25%?

 

[Faster Eddie]

This is what my Blueprint 347 put up with C4/35"s/4:56 gears

 

[sykanr0ng]

Not very impressive below 4000 RPM's.

Might be just the thing for a race car, but for a Bronco?

 

[Broncobowsher]

Trying to fin my old dyno sheet (that was 2 computers ago). I know I posted it at one time but I can't find it in my searches. Looks like it was in Bronco Driver #17.

I recall it being 250 HP and 300 torque. Torque curve was very flat, just a mild rise in the mid range.

Oh, it was just a 351. The affordable factory stroker. It did have the typical stoker parts to make it run good, a little compression, good heads, and a mellow cam.

 

[Faster Eddie]

Not very impressive below 4000 RPM's.



Might be just the thing for a race car, but for a Bronco?

I re-curved the dizzy since then. Much better now.