351w build, or 408?

[broncnaz]

There's a big differnace between diesel engines and gas engines yes some gas engines can be run at fairly low RPM's but it will never do what a diesel does. your loss in mileage proves that gearing is not there.
You want gas mileage then get a car. Put some half way decent gears in that thing a build the engine a little. Its more about matching components than it is just trying to run low RPM's. 456 gearing would probably be a good choice that will still keep the RPM's down and give you way better low end power not to mentyion good hiway cruising RPM's. You might find that you dont have to run in low range very often anymore so it will be availible when needed. Plus the better gearing will allow the clutch to live longer and you wont have to down shift on the hiway when you hit a hill.
While swapping to the cam you listed may help on the low RPM side your still not going to make anymore power than a stock cam. You just move the power band around a little if any. Almost every other aftermarket part out there really only makes more power at higher RPM's so usually from about 1600 RPM on up. adding heads wont help as they alone usually move the powerband up 400-700 RPM or more.

 

[addicted]

I dont think anyone has ever said you "cant" run 3.50 gears and big tires. And sure, a big cu motor "can" push it.. But its not effecient no matter what you tell yourself. I wouldnt consider any higher than 4.11s with that combo. You arent breaking any new ground with your theory. Youre putting undue stress on the motor by constantly running it below its efficent power band. I ran stock 3.50 gears and 36" Swampers in my 79 Bronco with a 460 for years. Always got around 9-10 mpg. Blew the 9" and put in 4.11s. After that I got 12mpg. Like previously stated. theres a reason EVERYONE is telling you to regear. But if you just want to be hard headed then do what you want. its your Bronco. I think a completely stock rebuild and gears would do better than a stroker with the gears you have. And good luck getting a cam recomendation. lol

 

[Devin]

If it's actually fine with the 37's & 3:50, your wasting our time asking for advice...

X2. These posts where the OP pretty much already has their mind made up are funny. They post a question, which they have already answered, then they defend against any advice that is contrary to what they have already decided.

408's are nice:

But I am guessing that isn't quite what you have in mind. ;D

 

[bmc69]

But I am guessing that isn't quite what you have in mind. ;D

Why not?

;D

 

[KyleQ]

I would say that is a wee bit overkill... but who cares! My 351W is coming out for a cam upgrade and exhaust upgrade this winter..

 

[ahansen_1985]

X2. These posts where the OP pretty much already has their mind made up are funny. They post a question, which they have already answered, then they defend against any advice that is contrary to what they have already decided.

408's are nice:

But I am guessing that isn't quite what you have in mind. ;D

I wasent asking about gears, all I was asking for was opinions on motor builds with a healthy torque rating.... As I don't know a lot about motor builds yet...


1966,351w,m5od,205....3.5" lift, 2" body, 38.5's

 

[ahansen_1985]

408's definitely a possible future build gotta save some serious finances....


1966,351w,m5od,205....3.5" lift, 2" body, 38.5's

 

[ahansen_1985]

I would say that is a wee bit overkill... but who cares! My 351W is coming out for a cam upgrade and exhaust upgrade this winter..

Over kill yes but hey that's what my bronco is....


1966,351w,m5od,205....3.5" lift, 2" body, 38.5's

 

[Amac70]

im not sure your mazada trans is going to hold up to the torque of the 408m's or a 408w for that matter.

 

[Devin]

im not sure your mazada trans is going to hold up to the torque of the 408m's or a 408w for that matter.

God just killed a kitten.....and a puppy.

 

[NYLES]

zf+513's+37's= 2001 rpm@55.........

Mazda+3.50's+37's=1398 rpm@55

You need gears! oh and I see your running a 205 (1.96:1) YOU REALLY NEED GEARS!

 

[ahansen_1985]

im not sure your mazada trans is going to hold up to the torque of the 408m's or a 408w for that matter.

That is one thing that did cross my mind lol, and i think your very correct....


1966,351w,m5od,205....3.5" lift, 2" body, 38.5's

 

[Broncobowsher]

If you read any other thread on engine advise; we look at how it is used, tire size, gearing, transmission, etc. and try and narrow it down.
When someone is going to do something very wrong, we point it out.
The gearing issue is so devastatingly bad that it completely overwhelms anything about building an engine.
I hope that you eventually see that NOBODY is on your side with keeping such a horrible choice in gearing. You think you know what you are doing, but you are just proving to everyone that you don't and are not willing to accept help from those who are willing and trying to help you.

 

[1snowcat]

X2 on the gear change.............. You wont be sorry!!! And way cheaper than silly bling parts anyway in the long run.

 

[NYLES]

http://www.grimmjeeper.com/gears.html

 

[Timmy390]

I know you just want to put around but I think I would TRY current motor and gears first before I went done that rabbit hole of a stroker. Gears (got mine on ebay) $112 plus shipping. Stroker kit, $2K.

I did a gear change this summer and LOVE IT.......

Tim

 

[KyleQ]

Over kill yes but hey that's what my bronco is....


1966,351w,m5od,205....3.5" lift, 2" body, 38.5's

Ahh, I wouldn't call it overkill after comparing my setup.. which is overkill. MDO5? Please - that wouldn't last an hour with my driving...

 

[ahansen_1985]

Ahh, I wouldn't call it overkill after comparing my setup.. which is overkill. MDO5? Please - that wouldn't last an hour with my driving...

Lol no not the m50d, the 2" 1/4 wall Dom steering, suspension, etc.... Overkill for the driving I typically do


1966,351w,m5od,205....3.5" lift, 2" body, 38.5's

 

[BALCH-Autoworx]

In the interest of getting back on topic, I am seriously considering going this route to replace my tired (and currently dead) 351W: ATK 408W

I got one positive response in another thread about ATK Crate motors, any thoughts?

I am not sure I follow ahansen_1985's logic on his gear choice as gears and 37"s are on my long list but I am interested in talking 408Ws.

 

[KyleQ]

For that kind of money find your local pro assembler and hit the Mustang boards and get yourself a pile of parts and have someone loacl put it together. Vauge parts list, small cylinder heads and unknown cam - but has a warranty... Still is a lot of money - I was putting together a 427 build with premo top of the line parts and I wasn't even going to get to half of that bill...