351w buildup

[88stanggonebad]

im getting ready to buy a new engine for my 67 mustang coupe and decided to throw out the 289 for a 351w. what do you guys think would be the best combo for a 400 to 450hp build. this car will just be driven on the street and probably never see the track. it will be backed by a c4 tranny and 3.55 gears. gas milage and idle quality are not a concern for me.

 

[jerry S]

im getting ready to buy a new engine for my 67 mustang coupe and decided to throw out the 289 for a 351w. what do you guys think would be the best combo for a 400 to 450hp build. this car will just be driven on the street and probably never see the track. it will be backed by a c4 tranny and 3.55 gears. gas milage and idle quality are not a concern for me.

You can get 420 hp from a 351W easy without stroking it. I have 420 hp at the fly with my 351W. here is my combo

forged rods and flat top pistons with 10.5 CR.
Edelbrock RPM Performer cylinder heads
Edelbrock RPM Air Gap intake
650 cfm vacuum secondary carb
hefty cam:

INTAKE: Duration: 297º Lift: 0.538
EXHAUST: Duration: 308º Lift: 0.534

Duration at .050"
Intake: 236
Exhaust: 242

You could get even more hp with AFR heads and even more with a 393 stroker

 

[D.Hearne]

Start with a 94-up roller 351W. Add flat topped pistons. Add your choice of aftermarket heads. Add your choice of off the shelf hydraulic roller cam. ( I used a new, second hand Z303 roller in my 331 and got excellant results) Add your choice of aluminum intake.(I'd go dual plane for better bottom end streetability) Rods? all 351's in addition to all other Ford pushrod V8's got forgings, just some are better than others. Stockers are fine to 6500, maybe more with good bolts. Isn't hard to do with a roller cam and aftermarket heads.

 

[Max Power]

Jerry, did you dyno your motor to get that HP rating? I ask becasue I have a 393 version of what you have.

 

[jerry S]

Jerry, did you dyno your motor to get that HP rating? I ask becasue I have a 393 version of what you have.

Yes. I originally dynoed at 300 rwhp with all kinds of things not being right.

First, the first shop that did my tune stole my new Autolite AR 3924 plugs that I had just gapped and installed prior to driving to them and replaced them with a bunch of old plugs lying around. All different mfgs, all different heat ranges, all different gaps.

The first dyno tuner locked out my total timing to 28 degrees and left my carb jetted running very rich.

I still had a poorly configured dual exhaust system at the time.

With all of that, I still pulled 300 rwhp. Subsequently, I had an X pipe junction installed. I really felt the difference when I was driving it. The torque and throttle response was explosive compared to before. I then had the car re-tuned. Prior to doing anything to the timing or the carb, the car was dynoed and it put down 315 rwhp. I picked up 15 hp just from installing the X pipe. Then I had a programmable MSD timing computer installed along with the new torque converter. the car was tuned and redynoed again (this time with A/F ratio being tested, something the first shop said it does but does not). My total timing was advanced from 28 to 34 degrees, the carb rejetted, and I got 329.9 at the rear wheels with a proper A/F ratio. I have a C6 tranny so I am figuring 22% loss through the drive train.

 

[88stanggonebad]

im getting ready to buy a new engine for my 67 mustang coupe and decided to throw out the 289 for a 351w. what do you guys think would be the best combo for a 400 to 450hp build. this car will just be driven on the street and probably never see the track. it will be backed by a c4 tranny and 3.55 gears. gas milage and idle quality are not a concern for me.

would afr 185s be good enough? i was thinking a stock rebuilt 351 with 185s afr heads a performer rpm air-gap intake with a road demon 725cfm carb with some long tube headers. what cam do you recomend and what hp do you think i could achive with this set-up

 

[jerry S]

would afr 185s be good enough? i was thinking a stock rebuilt 351 with 185s afr heads a performer rpm air-gap intake with a road demon 725cfm carb with some long tube headers. what cam do you recomend and what hp do you think i could achive with this set-up

AFR 185s would be perfect for a 351W through 393W stroker. The cam you get would depend on how high in the RPMs you make your peak hp. If you end up not stroking it, keep in mind that stock crankshaft is not designed to spin past 6K RPM for very long. The cam I have in my car (see the specs above) is a Crower 15237 and it makes power to 5900. If you get a stroker in the future, you will get a new crank anyway that will be able to spin past 6K RPM ok. Just pay attention to your bottom end as a stroker will put added wear and tear on your engine. For now, I think the carb is not too much. Larger carbs make more HP at the high end but don't do so well down low. Unless it is a strip car, you will have more fun accelerating from a light or passing so the smaller carb is perhaps a better idea. I have a 650 vacuum secondary on mine and it runs great. There was no indication that I was starving for fuel at 6000 rpm on the dyno.

 

[DK832]

I run a Sportsman block, forged pistons & rods and Edelbrock RPM heads giving 10:1, Ford X303 cam, Ford P351 dualplane intake and a 750 Holley. Very streetable and definitely no dog. Still have some minor tweaks before it goes on the chassis dyno so no numbers yet.

 

[jerry S]

351W in a 1967. The AFR 185s are a great choice.

Intake: You might have some fitment issues with an RPM Air Gap on a 1967. The RPM intake is basically the same as the stock 351 intake so there is no advantage to it. The RPM Performer is a better intake. Some guys really like their Weiand Stealth intakes.

Headers: Long tubes are best but there are almost always fitment issues.

Pistons: forged pistons at between 10.1 and 10.5 CR are the way to go.

Rods: forged I beam rods would be recommended for a 400 hp engine. Some guys like to run a longer rod like from the 351M. This allows you to run the higher CR (10.5 or even a touch more and more advance in your timing. Both of which = more power). Speed-o-motive sells a 351 long arm package that they advertise as making 465 hp.

Carb: 650 should be fine but others like the 750s.

Stall converter: depends on the cam and power band but an off the top of my head guess would be something around 2500 or slightly higher.

Cam: The cam in my car is awesome for a street rod making its peak power at less than 6k. Crower 15237

Pay attention to your bottom end if rebuilding. You would also want to upgrade to a new harmonic balancer. You could get 400+ hp very easily from a 351W with AFR 185s. That is about as much as you would want from a street car in my own uninformed opinion.

 

[D.Hearne]

If you end up not stroking it, keep in mind that stock crankshaft is not designed to spin past 6K RPM for very long.

I think you're under-rating the stock crank. The only weak stock Ford cranks I've seen are the early 50 oz/in 302 cranks. I'd be more worried about the stock rods in a Windsor, mainly the early ones with the oiling bosses for the pins.

 

[DK832]

I think you're under-rating the stock crank. The only weak stock Ford cranks I've seen are the early 50 oz/in 302 cranks. I'd be more worried about the stock rods in a Windsor, mainly the early ones with the oiling bosses for the pins.

Agree, I rev to 6.500 with a stock. Chamfered oil holes etc.

 

[Stangninjak]

See my Mods in my sig. I run that in a 65 coupe. I have a blast in this car as the power is truly down low. I easily pull on cars with this combo, and still get decent mpg. I run the HSA 670 vac carb. Does a truly bang up job(Thanx D hearnes) and tbh, I think I need to get a stronger clutch because the stock 3 finger one seems to be slipping some now..I plan on getting to dyno soon, hopefully this week.

 

[Edbert]

~420fwhp from a 351W is easy, you can get that figure and have a very broad and flat torque curve too. I suggest limiting your revs to 6,500, if you wanna go higher than that with those huge journals it is gonna cost you big $$$ and the returns are diminishing fast at that RPM.

Regarding height...I got a RPM manifold (non air-gap), a 750 vac-sec Holley, a 3" airstream and a 1" phenolic spacer atop a 351W in my '67 vert. I had to grind the bolt almost flush with a low profile nut to clear a 67 Shelby hood, According to my ball-o-clay I got a bout 1/8 inch of clearance, I have the prothane mounts because if I lose a motor mount i also lose a hood

 

[BLK91LX1uponu]

Early 351w cranks are good to 750hp... I don't think the Z-cam is a small base circle grind cam so you would have to use it in a late model windsor.

 

[65up2d8]

Early 351w cranks are good to 750hp... I don't think the Z-cam is a small base circle grind cam so you would have to use it in a late model windsor.

I'm not speaking from actual experience, unfortunately, but its my understanding that you would really be in the danger zone of splitting a 351W block at 750 hp. Further,
from what I understand with respect to the Z cam, you just can't use it, or any standard base circle roller cam for that matter, with the cheaper roller cam conversions in a non-roller block. However, if you buy the $400 plus link bar style lifters, which I believe both Comp and Crane offer, you can use a standard base circle roller cam in a non-roller block.