331 or 347??

[Project 77]

Hello ladies/gentlemen....I have a question. I have a 95 GT has a 302 X cam, 24 poiund Injectors yadda yadda. Thie winter I want to replace the motor with a 331 or 347 what I want to know is which one is the prefered motor? This car is pretty much a weekend driver and it will see the dragstrip. Not very concerned about fuel mileage, just how well it runs. thanks again...i'l post some pics this week of the green monster

 

[Rockin95Stang]

I have a 331 built by Keith Craft and love it. Produces great power/torque for the set-up that I have and runs excellent right out of the crate. Only have 6,000 on it right now, so I'll see how it holds out in the long run. So far, no complaints.
http://www.keithcraft.com/index.htm

Hello ladies/gentlemen....I have a question. I have a 95 GT has a 302 X cam, 24 poiund Injectors yadda yadda. Thie winter I want to replace the motor with a 331 or 347 what I want to know is which one is the prefered motor? This car is pretty much a weekend driver and it will see the dragstrip. Not very concerned about fuel mileage, just how well it runs. thanks again...i'l post some pics this week of the green monster

 

[93cobra12]

If i was to get a stroker motor I would too get a 331.. Its alot more realiabe I heared an they have a great top end.. TQ isnt as torquey as a 347 but once you get up there it'll take a 347 any day.. As of right now im saving up for that motor, I was looking at kieth craft myself but decided to have a custom built motor.. If not It will be between keith craft or bennit racing.. But If i were to choose I would go with a 331.. All the way !!

 

[ray95]

If i was to get a stroker motor I would too get a 331.. Its alot more realiabe I heared an they have a great top end.. TQ isnt as torquey as a 347 but once you get up there it'll take a 347 any day.. As of right now im saving up for that motor, I was looking at kieth craft myself but decided to have a custom built motor.. If not It will be between keith craft or bennit racing.. But If i were to choose I would go with a 331.. All the way !!

check out imbperformance.com These are some of the guys that used to work at keithcraft.

 

[Killercanary]

I'd go 347 without a doubt. Why give up the extra cubes? Reliability issues and oil consumption problems are rumors. There are MANY 347's out there that live a hard yet healthy life.

 

[GTWayne]

Which one 331/347

If i was to get a stroker motor I would too get a 331.. Its alot more realiabe I heared an they have a great top end.. TQ isnt as torquey as a 347 but once you get up there it'll take a 347 any day.. As of right now im saving up for that motor, I was looking at kieth craft myself but decided to have a custom built motor.. If not It will be between keith craft or bennit racing.. But If i were to choose I would go with a 331.. All the way !!

Depends on how long you want it to last and how much power you want to make. Just because of what makes the extra cubic inches from a "stroked" motor: distance the piston rod on the crank travels, lengthening the distance the piston travels up and down means the rod angle is more acute and increases stress on the cylinder wall since the piston is pushing more toward it than up and down: 347 would then theoretically have a shorter life expectancy. They are both capable of producting a lot of power and torque over the stock 302.

A good compromise is the 331 since it has a longer wear expectancy, great power and torque potential. However there are guys out there making a lot of power w/306 combos too.
Wayne

 

[DavidF]

Hi Im new to this forum but not new to Mustangs. I have an CHP 347 and love it. I have about 10k on it so far with out any complaints. I drive it every day its my only car. It doesnt consume any more oil then when it was stock.

 

[Killercanary]

Welcome David!

 

[95snoozer]

get a 342... so you can have the block honed and rebuild it if you ever have isses...problem solved

 

[moneypit94]

Im a little bias with the 331, but i think that both are good choices. I would suggest getting some good rods though.

If your building a motor you need to think about a few things.

Are you eventually going to put a blower on it, or run the piss out of it? If so you might want to just start off with a decent block (dart, sportsman, r302, or even an F302 block ) And if your going to add a supercharger or a turbo then you will want to start off with a lower compression.

You don't have to do any of that but you start to play with fire if you don't.

But either way you go, 331 or 347, if done right can be very dependable engines.

 

[Killercanary]

F302??? What is that, I'm not familiar with that one.

 

[moneypit94]

F302??? What is that, I'm not familiar with that one.

M-6010-F302 302 Race Block-4-Bolt Main Caps(8.200" Deck)Aluminum $3499.99

A bad boy of a block...

M-6010-B50 302 Heavy Duty "Sportsman" Block(8.200" Deck)Cast Iron $999.99
M-6010-R302 302 Race Block-4-Bolt Mains on #'s 2/3/4(8.200" Deck)Cast Iron $1799.99
M-6010-S302 302 Race Block-4-Bolt Mains on #'s 2/3/4(8.700" Deck)Cast Iron $1799.99
M-6010-F302 302 Race Block-4-Bolt Main Caps(8.200" Deck)Aluminum $3499.99
M-6010-F87 302 Race Block-4-Bolt Main Caps(8.700" Deck)Aluminum $3499.99

these part numbers are according to need-4-speed (seem to be FMS numbers)

 

[Killercanary]

Ohhh.... I don't think that block is available though anymore. If it is its a new introduction piece as FMS used to sell an all aluminum blokc but discontinued it years ago, same with the old A4 block which was the pre-R block.

 

[Sup95Cobra]

I would go with a 331 if the car will see more street duty and a 347 if it will see the track more!

 

[buzntxn]

well the biggest stroker kit i've seen is 348, there's no replacement for displacement, quit playin around and just buy a 351w or bigger is better

 

[sbford]

my vote is for the 347, like killercranary stated, there are to many stories about 347s having rod problems and oil consumption concerns. IT DEPENDS ON WHO MACHINES THEM AND BUILDS THEM!

Thats my thoughts
Nate

 

[67stang390]

I'm building a 347 right now for my 94 GT daily driver. Yes, it's true the 347 has a higher rod ratio than a 331, which puts more stress on the cylinder walls. However, the 347 also starts making power at lower RPMs, so as far as lasting longer, I'd say it comes down to how well the engine is built. Also, most of the oil burning problems you hear of were solved years ago. People burn oil in any incorrectly built engine, be it a 347 or a 306.

 

[moneypit94]

Ohhh.... I don't think that block is available though anymore. If it is its a new introduction piece as FMS used to sell an all aluminum blokc but discontinued it years ago, same with the old A4 block which was the pre-R block.

that would exlpain why i could really only find it on one website. Could be that they have some left over too?

 

[Eric94GTvert]

that would exlpain why i could really only find it on one website. Could be that they have some left over too?

@ $3,500, I'd imagine they have a bunch left over.

 

[ProKiller]

what would you suggest for a supercharged engine. I was lookin at DSS for a 331 short block b/c the 347 said for "mild boost" which makes me a little bit nervous about it. I plan on running something in the area of 15#s. what you guys think?