331 vs 347 Stroker

[Kegger]

My 331 does just fine it digs in without sitting and spinning. eddy perf 3128 efi 70 tb 75 pro m 30 lb inj 95 fuel rail trick flow 190 cc heads and a custom , cam this is very important 264/273 .521/ .531 lift@.50 dur 216/220. The only off the shelf cam thats close is the comp xe264 will work with the stroker you gain the torque with the stroke so you can increase lift but because its a 4.500 lbs truck you gota watch the duration of the cam,, 10-4 call comp the'll spec the cam to your wieght and lift and gears and tires ect ect, cost only 75. more over some shit you wont like and you can do it with a gt 40 top. cheep enough and some 1.94 valve e-7 heads but to cut the wieght some 170, to 180s will do. mine 400hp @ 5800 which is about 250-300 hp in the 4x4 trail mode which is pleanty of power I don't have idle issues and she runs fine, and a blast on the street. 5200 shift points @ wot and runs mid /upper 12s @ the track. they all cost the same. go big and mine was about 7K to do with all the extra stuff. the w is much more cost effective. 408 for a grand or 2 more your call.

 

[Rymadd]

I built a 331 for my 66 mustang because 351s are a really tight fit in those, and with the headers and Power steering a windsor wouldn't have fit. I have read and my machine shop said that the 347 kits start to hav really extreme rod angles and such that they drastically decrease the life of the motor, a 331 is closer to stock and you can still get 150,000 miles out of a motor. Just my 2 cents, also think that is why people do 408 windsors instead of the 427.

 

[rguest3]

I have built One 331 and 2 different 347s and would do again.

Scat 347ci Stroker Kit
Comp Cams - XE266HR Roller Cam Kit
AFR 185 Heads
9.4 to 1 Pistons
Edelbrock RPM Manifold and 600cfm Holley.

This combo did extremely well. Great torque improvement and 5500 RPMs was easy as well. Finished it off with stock valve covers and other original Bronco engine pieces to retain the original look. Completely looked stock from the outside, quite the "Sleeper" motor.

 

[Ourobos]

302 parts make 302 power..

I've built anything from 331s to 418s.. Even if you reach the magic 1 hp per cubic inch, you're not talking about a whole hell of alot of power difference between them. The trick is reaching it. Some 165-185cc heads, a mid range intake (GT40 style), and a good possibly even custom RV cam will put you where you want. Sounds like a fun combo with the NV3550.

 

[baddad457]

The 331 in my Comet does fine in a truck, had it in an 89 Ranger for 2-3 years. Only thing that needs to be different is the comp ratio (it's 10.4 to 1) Stock 89 Roller block, Eagle crank, SRP pistons, SIR rods, Ford Racing Z303 cam with 1.7 Comp cams rockers (.587 lift, 228* @ .050, 112* LSA) Canfield heads (AFR 165 equivalent) Repop factory 3x2 setup with 3-250 cfm carbs. Power comes on at 1500, pulls to 6500. Requires 92 octane fuel with this cam and compression. Awesome bottomend torque, far more than a 302 will generate.

 

[Broncobowsher]

I have built One 331 and 2 different 347s and would do again.

Scat 347ci Stroker Kit
Comp Cams - XE266HR Roller Cam Kit
AFR 185 Heads
9.4 to 1 Pistons
Edelbrock RPM Manifold and 600cfm Holley.

This combo did extremely well. Great torque improvement and 5500 RPMs was easy as well. Finished it off with stock valve covers and other original Bronco engine pieces to retain the original look. Completely looked stock from the outside, quite the "Sleeper" motor.

Now build a 351 and tell us what you think of that.

Yea, you built a couple of 302 based engines. Yes they can run good. But without a 351 reference point you can't rule them out. It's like saying the straight 6 is good, and you can make them run really good. But never have driven a V8 to know what it can really be like.

 

[rguest3]

Broncobowsher - The above stated engine build is the same build I am currently doing for my 77 Frame off...... But with an EFI GT-40, 351w instead. My 69 has the 351w with exact build and Carb.

I'm with you on the 351w. Have 2 of them. The initial post was asking about a 331-347 and seems to have his mind made up, and the same combo worked almost as well.

 

[AZ73]

You're using an NV3550. You can use a somewhat stock 351, but if you start getting the Torque over 400, then your transmission isn't going to last. Now you'll have to think about a NV4500 to hold up to a stroked 351 which then requires lots of other changes. Yes, a worked 351 or 408 puts out gobs of power. For what? It comes with a lot of other changes to install it and a weight and center of gravity penalty. My 347 is putting out 400 ft/lbs and 400 HP, and the torque comes on at 1200 rpm, being all in by 2500. I rev-limited it to 6000. It will spin past that but adds nothing since I'm running a 5 speed. I can just shift to the next gear and keep going. Plenty for a bolt in, non-modified installation and for the NV3550. Use the 347 and change your gear ratio to match your tires. If you want to go 351, it should be for generating more torque than 400, and then you'll have to change the trans (which adds weight), drive shafts, body lift, brackets, and a bunch of other things. Or just switch to an automatic 3 speed or OD. And lets face it. How often are you using more than 400 Ft/lbs? Unless you only have a 3 speed with a 3.08 rear or plan on spinning 4000 RPM at 70 MPH, or are running 37's in which case you'll have to change your axles too. Look at your entire drive train, then think about how you want to drive it. Think about how much gas you want to burn, and think about the TYPE of gas you want to burn. To get the power from a 347, you'll need more than 9.0 compression so it's not going to run on 87.

 

[latrucker]

I went the 331 route after much discouragement from the audience. Went with AFR 165 heads, custom cam from Comp (212 int / 218 exh, .560 lift 110 LSA) Quick fuel SS 680 carb and weiand street warrior intake. Its a beast of a motor. Tons of bottom end and didn't stop making power on the dyno till 6000 rpm. Max torque was at 3800 rpm. Made 340 ft\tq at 2500 rpm which is where the dyno starts measuring. Although I am currently having thrust bearing issues and had to pull the motor, once I get it back in you are welcome to come take it for a spin and see if a 331 will suit you needs. Should have it back up in 3 to 4 weeks. I am in Lafayette.

 

[baddad457]

Was wondering what the Street Warrior was, looks like Weiand renamed the Stealth.

 

[latrucker]

Was wondering what the Street Warrior was, looks like Weiand renamed the Stealth.

Its more like Weiand's version of the Performer. Somewhat stockish aluminum intake. Step under the Stealth.

 

[Fairlane514]

You can also build a 347 using a shorter rod....5.315 vs. 5.400. It keeps the wrist pin out of the oil ring landing on the piston.

I plan on this when building my 347.

 

[baddad457]

Its more like Weiand's version of the Performer. Somewhat stockish aluminum intake. Step under the Stealth.

From the picture I saw it's a carbon copy of the RPM, not the Performer.

 

[latrucker]

From the picture I saw it's a carbon copy of the RPM, not the Performer.

Nope! I own both and it is shorter than the RPM. Very compatible to the performer. I am removing the street warrior and installing the RPM in a few weeks, I will put them side by side to compare. Eyeballing them, the Rpm is noticeably taller and from what I read much more efficient.

 

[AZ73]

I built a 331 for my 66 mustang because 351s are a really tight fit in those, and with the headers and Power steering a windsor wouldn't have fit. I have read and my machine shop said that the 347 kits start to hav really extreme rod angles and such that they drastically decrease the life of the motor, a 331 is closer to stock and you can still get 150,000 miles out of a motor. Just my 2 cents, also think that is why people do 408 windsors instead of the 427.

Lot of people comment about the angle, but the Chevy 383 stoker angle is "worse". It's one of the most popular strokers on the planet and they last forever. It's a theoretical issue, but not a practical one. 347s that don't last are because of bad machine work. If you belong to a forum like SBFTECH.com people build 331s and 347s that crap out after 500 miles from side load. It's always because of bad machining work. Tons of people there have over 100,000 miles with no oil issues and running fine.

 

[baddad457]

Nope! I own both and it is shorter than the RPM. Very compatible to the performer. I am removing the street warrior and installing the RPM in a few weeks, I will put them side by side to compare. Eyeballing them, the Rpm is noticeably taller and from what I read much more efficient.

Let us know, pics would help. Until you mentioned the Warrior I was unaware of it. Sure looks like the RPM and Stealth though