351w build, or 408?

[ahansen_1985]

So I'm thinking of a winter build for my bronco, currently run a worn out 1971 351w.... With a few bolt on goodies...
Current setup is
Weiand stealth intake
Edelbrock carb
Long tube headers w dual 2.5 exhaust
Elec fan
------
Mostly a low rpm driver... 37's with 3.50 gears, and a 5 spd manual rarely hit 4000rpm... Cruises at 17-1800 in 5th, 2-2100 in 4th

Needs a bit more torque

Is it better to build up the 351? Or stroke it?
What setups are you running motor wise? With good torque #s and decent hp?


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

 

[ahansen_1985]

I should add this is Gonna be a more budget friendly build lol....


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

 

[Broncobowsher]

Put some gears in it. That will do more for adding torque (driving force) then engine upgrades.

 

[broncnaz]

X2 on the gears. 3.50's and 37's not a good combo unless you like using low range all the time.
Since its a budget build stick with a 351. IMO any stroker needs heads. Most stock engines also can use upgraded heads as the factory heads are not real good to begin with. even the factory's so called good heads fall short.

 

[ahansen_1985]

It's actually fine with its current gears... I use low range for my offroading, it's actually quite nice in the mud and sand. Don't need it anywhere else....
It pulls 5th now with a tired motor....that's stock...


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

 

[StnePny]

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

That's why they have " Calculation Charts "

wheel size x rpm = gears (thsi is just an example)

i don't remember the site, but, I sure someone will chime in with the info needed.....

 

[ahansen_1985]

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

That's why they have " Calculation Charts "

wheel size x rpm = gears (thsi is just an example)

i don't remember the site, but, I sure someone will chime in with the info needed.....

Lol well said, what I was meaning Is that I like the Rpms where they are at, just workin my old motor a bit to pull them.... Figure if I add some power, pull the gears with with less motor load, and hopefully keep some resemble of milage....


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

 

[Broncobowsher]

Quit lugging the motor and the mileage may just go up. I bet you would actually get better mileage in 4th gear then you get in 5th with what you have now.

 

[ahansen_1985]

For now that's true, but I'm quite sure with a lil pep added to my motor then I can make use of my gears.... The motor I'm Runnings older than I am by a good bit.... Hasent been built ever... Yet...if that doesn't do what I'm wanting then yes ill slightly re-gear


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

 

[broncnaz]

I think you'd be real suprised what the correct or at least better gearing will do. That motor is tired because of gearing more than just being old. If you like the RPM's you run now then you wont be building a engine for more power you will build it to make all its power way down low. Low RPM engines rarely make more power than a stock engine will.

While it helps to have a engine with more pep more pep is usually made at higher RPM's. Where the gearing will give you more pep at all RPM's

 

[bronconut73]

So I'm thinking of a winter build for my bronco, currently run a worn out 1971 351w.... With a few bolt on goodies...
Current setup is
Weiand stealth intake
Edelbrock carb
Long tube headers w dual 2.5 exhaust
Elec fan
------
Mostly a low rpm driver... 37's with 3.50 gears, and a 5 spd manual rarely hit 4000rpm... Cruises at 17-1800 in 5th, 2-2100 in 4th

Needs a bit more torque

Is it better to build up the 351? Or stroke it?
What setups are you running motor wise? With good torque #s and decent hp?

Wow a stroker is costly since you'll need some good flowing heads to realize it's potential. You will be a couple grand into it and not get as big of a bump in perceived power and genuine mileage as well.
The guys are right though you will get a real kick in the pants by re-gearing and with 37's and 3.50 gears, YOU REALY NEED TO RE-GEAR!
You will definitely get better gas mileage too. No matter how you slice it you are geared way to high for 37's my bronco brother.

 

[70_Steve]

I do agree with the others that you're doing the engine a dis-service by running the low (numeric) gears.

I run a 351, bored .040, stock pistons with the block decked to increase compression to 9.0-1 and reduce quench height to ~ .040. Stock E6 heads (huge 69cc chamber) with the exhaust hump removed. And a Comp Cams recommended cam for low end torque. Made 187 hp @ 2200 rpm and 286 torque @ 4400 rpm. And I've got some tweaking I can do.

I run 4.56 gears with the NV4500 (.76 overdrive) and 35" KM2s. I'm taching 2200-2250 RPM @ 65 mph, and a couple weekends ago averaged 14 MPG for 4 hours of highway driving. I'm very happy with the gearing, both on the road and off!

 

[KyleQ]

I would say cylinder heads and/or cam would get you want you want without spending too much or working too hard to get there. Gears are easy to say, but that is a lot of work-

 

[ahansen_1985]

I'm kinda thinking a cam set.... Anybody using this cam set?
http://www.compperformancegroupstor...roduct_Code=K35-231-3&Category_Code=FTCAMSX4X



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

 

[Broncobowsher]

I'm kinda thinking a cam set.... Anybody using this cam set?
http://www.compperformancegroupstor...roduct_Code=K35-231-3&Category_Code=FTCAMSX4X



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

Cam Style Hydraulic flat tappet
Basic Operating RPM Range 1,000-5,000
Intake Duration at 050 inch Lift 206
Exhaust Duration at 050 inch Lift 214
Duration at 050 inch Lift 206 int./214 exh.
Advertised Intake Duration 250
Advertised Exhaust Duration 258
Advertised Duration 250 int./258 exh.
Intake Valve Lift with Factory Rocker Arm Ratio 0.448 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio 0.483 in.
Valve Lift with Factory Rocker Arm Ratio 0.448 int./0.483 exh.
Lobe Separation (degrees) 111
Grind Number FW X4 250H-11
Computer-Controlled Compatible No
Lifters Included Yes
Lifter Style Hydraulic flat tappet
Valve Springs Included Yes
Outside Diameter of Outer Spring (in) 1.437 in.
Retainers Included Yes
Locks Included Yes
Valve Stem Seals Included Yes
Timing Chain and Gears Included Yes
Timing Chain Style Double non-roller
Assembly Lubricant Included Yes
Pushrods Included No
Rocker Arms Included No
Gaskets Included No
Valve Springs Required No


Still won't do squat for running the wrong gears. Probably run even worse.

Anytime your gearing is so far off that you can run highway speeds in low range, your gearing needs changing. Take that cam money, buy a set of cheap 4.56 gears just for the 9". Go for a drive. Then you will want the matching set for the front.

Three is a reason EVERYONE is telling you to put gears in it.

 

[ahansen_1985]

There's also a reason with my 35s I used to have and the same 5 spd that I got 15-17 mpg.... And even now with 37's I get 14's same concept as diesels.... Use low Rpms plus efficient torque to gain milage


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

 

[bronconut73]

Cam Style Hydraulic flat tappet
Basic Operating RPM Range 1,000-5,000
Intake Duration at 050 inch Lift 206
Exhaust Duration at 050 inch Lift 214
Duration at 050 inch Lift 206 int./214 exh.
Advertised Intake Duration 250
Advertised Exhaust Duration 258
Advertised Duration 250 int./258 exh.
Intake Valve Lift with Factory Rocker Arm Ratio 0.448 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio 0.483 in.
Valve Lift with Factory Rocker Arm Ratio 0.448 int./0.483 exh.
Lobe Separation (degrees) 111
Grind Number FW X4 250H-11
Computer-Controlled Compatible No
Lifters Included Yes
Lifter Style Hydraulic flat tappet
Valve Springs Included Yes
Outside Diameter of Outer Spring (in) 1.437 in.
Retainers Included Yes
Locks Included Yes
Valve Stem Seals Included Yes
Timing Chain and Gears Included Yes
Timing Chain Style Double non-roller
Assembly Lubricant Included Yes
Pushrods Included No
Rocker Arms Included No
Gaskets Included No
Valve Springs Required No


Still won't do squat for running the wrong gears. Probably run even worse.

Anytime your gearing is so far off that you can run highway speeds in low range, your gearing needs changing. Take that cam money, buy a set of cheap 4.56 gears just for the 9". Go for a drive. Then you will want the matching set for the front.

Three is a reason EVERYONE is telling you to put gears in it.

Yup, yup, yup. I know how he feels though. Not so long ago I would have much rather installed a cam than to tackle a ring and pinion.
I was genuinely afraid of that rear axle. Avoided it for years no decades. I would do the next performance engine part.....putting off the re-gear over and over.
After having completely built my rear axle, detroit, 31 spline BC axles, G2 gears (4.11), and BC's rear disc kit, etc.....
I sooooo wish I had done it sooner. Just going from 3.50 to 4.11 has made such a nice difference all over the tach. It has been a better over all improvement than the cam, intake, holley TA, duff headers, etc...

 

[ahansen_1985]

Oh I've been into my gears already, I set it up with low Rpms at 55-60 mph in mind.... I've built my entire truck.... Ground up....I'm simply doing what many say cannot be done....


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

 

[ahansen_1985]

If the motor doesn't end up as I'm wanting the ill go for some 3.73's or so


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

 

[samuel5090]

You need to listen to these guys.

Changing to 3:73's will do nothing. I have 4:56 in mine and only run a 33 inch tire. I can cruise at 65 at just over 2000.

I have a 408 in my Mustang and it is wonderful for torque. If you do a full rebuild going to a stroker will not cost that much extra. Put the stock heads back on it after a clean up-you can always change them later. That cam looks "OK". ANd put gears in it