347 Help

[NewStangOwnr]

I'm in the process of buiding a 347, and am on a kinda limited budget.

Over the summer I plan on adding boost, so I would like do build it right, now instead of later.

So forged crank,rods,pistons,etc. Any on kits people have used? I plan on going with a 5.315 rod instead of the 5.4 for the oil ring problem.

I have enough to cover the stroker and machine work, and maybe 9-1g after that.

I would like to do a roller cam maybe? Rocker arms? Or should I leave everything and just get AFR 185s?

Thanks for the help, I cannot decide.

 

[65fastbackresto]

I almost went a 347

Could have afforded it too, but I`m glad I didnt. My builder did a mild build on a 302,10 to 1 compresion with edelbrock heads and intake, and this thing will scream. Unless your planning on racing I`d stay with the 302, it`ll surprise you if you build it just a little I bet.

 

[65fastbackresto]

I almost went a 347

Could have afforded it too, but I`m glad I didnt. My builder did a mild build on a 302,10 to 1 compresion with edelbrock heads and intake, and this thing will scream. Unless your planning on racing I`d stay with the 302, it`ll surprise you if you build it just a little I bet.

Anyway I looked at some Eagle rotating assemblys, check em out, heard good things mostly about them.

 

[coolblue65]

I love my 347!!!!!!!! it was a night and day difference from my built 289 that I took out.

Anyways, the first thing is, what is your budget? And why do you want to boost it? only reason I ask is that you can and will make tons of power from a well built 347 without boost.

I ended up using a DSS (forged pistons and rods & balanced) shortblock w/AFR 185s (you can see the details in my Cardomain page) keep a look out out on some of the forums and you can probably find a good deal on new parts from someone who changed their mind.

 

[Hack]

Well, this isn't the advice you're asking for, but a strong 347 with boost means your block will probably not last very long. It would be a huge waste of money to build this thing and have it blow up in short order.

I don't see what year your classic is, but a 351W is a lot stronger block to handle more power. It will fit in the older Mustangs. For about the same money as your 347 you could have a 408 and a much stronger base for performance.

What are your goals? If you are all about straight line performance you'll get a cheaper, more reliable end product with a big block. If you really want a boosted 8.2" deck block, I'm thinking you should look at Dart or World (or the new Boss block at a minimum).

 

[NewStangOwnr]

I plan on boost for over the summer, and I already have a Dart 302 bolt, 4 bolt mains,etc. I'm saving it for the summer, I just want the 347 because I spun a rod bearing and would rather get the stuff now instead of later.

How much power are you making coolblue?

 

[coolblue65]

I plan on boost for over the summer, and I already have a Dart 302 bolt, 4 bolt mains,etc. I'm saving it for the summer, I just want the 347 because I spun a rod bearing and would rather get the stuff now instead of later.

How much power are you making coolblue?

Unfortunately I haven't been able to get the car to a dyno yet, but I am sure its somewhere around 430-440HP at the flywheel. There are several other members of the forum who have almost the exact same combo as mine and are running low 11's in the 1/4 with slicks. I only made it to the track once with the new motor, and my best on small street tires is a 13.2@109.

If the salt clears up here I might try to get it dynoed before spring.

 

[NewStangOwnr]

Cool. I was talking to a local shop and they said that some 347s that they've seen have been around 4xx at the wheels. But any advice on what to do?

 

[theautomatics]

Hey coolblue65, I'm over in Norridge. I've got a blue 67 mustang coupe with a 331. Maybe I'll see you at the grove eh?!

Why not go with a 331 stroker and use boost? You still have enough wall strength with a 331 for that kind of compression. I've got a 331 with afr 185's right now and I'm going to set it up for boost this spring.

 

[jcode68]

I swapped in a 347 with AFR 185's and the car is scary fast, couldn't imagine adding boost for the street. If your goal is racing, then you probably want to take a different direction as others have pointed out. I haven't dynoed my car yet, but CHP claims 405 hp, 420 ftlbs at the flywheel with my combo. Compared to my stock 302 that I replaced, it is a true night & day difference.

 

[Hack]

I swapped in a 347 with AFR 185's and the car is scary fast, couldn't imagine adding boost for the street. If your goal is racing, then you probably want to take a different direction as others have pointed out. I haven't dynoed my car yet, but CHP claims 405 hp, 420 ftlbs at the flywheel with my combo. Compared to my stock 302 that I replaced, it is a true night & day difference.

I believe that. I haven't had my '83 dynoed, but it probably makes less than 300 hp with 9.1 compression, a '93 Cobra top end and a Comp cams XE270HR-12. It makes me nervous when I'm pushing it hard. I think with 400 or more hp I would be afraid to use that power much on the street, and my car might not even be drivable 3 or 4 months out of the year.

 

[gp001]

my 347 made 338 rwhp with a wimpy cam and shutting down early on the dyno. 400 rwhp would be easy with a decent cam.

 

[Shakin66]

As an owner of a supercharged 347 I would have to say go for it. My car is docile enough for my wife to drive to the grocery store or if you want 400 plus HP its there. I have a 9# used powerdyne for $800.00 and while there are "better" s/c out there it has worked out great so far. I am also using Dart's pro one heads and have been really pleased there also. PM me if you want some pics or tech on my combo. I will latter be going F/I but I am having to much fun with this blow thru carb. Just be ready to spend some time thinking about your fuel system...