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What cubic inch motor?

  • Big bore 363

    Votes: 24 53.3%
  • Regular bore 347

    Votes: 7 15.6%
  • Big bore short stroke 347

    Votes: 7 15.6%
  • regular bore 331

    Votes: 2 4.4%
  • Stop wasting your money on this endless money pit because you need to save for retirement!

    Votes: 5 11.1%
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Discussion Starter · #61 ·
I voted for the 4.25 bore 347. I'm always torn on it, but, personally, that's what I think I would go with. 16 cubes is nothing to sneeze at but I like the idea of the big bore 347.

We may get to a point where there's no reason to ever not go with the 363. That time may be now as less and less people are messing with stock blocks and they're all the same price. Plus the rod ratio nonsense has proven to be just that.

Why has the 331 proven to be unreliable? Just bad luck?
Search "331 saga" in the Vintage Mustang section of this forum. Bad luck started by a short block bought from the Satan "AD Performance". Many factors come into play but the fact is if you bore a 0.030 over motor 0.030 over again and shove it out the door without even bothering to hone out the lifter bores bad things are going to happen. I could have at this point bought two 363's or whatever from Woody for what I have have in my current pile and it never fails to disappoint frequently.
 

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I tried to talk you out of it like you asked. Meh.
Get the aluminum block. Money comes and money goes. You're not going to live forever so go for it while you can.
 

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I gotta know. Who are the eight jokers who picked either of the "regular bore" options?
 

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I just built a big bore 347. I opted not to go with the 363 for the better rod ratio (yes, I know rod ratio is not an issue, but I tend to err on the conservative side) and because I didn't think I'd miss the 16 extra cubes on what is basically just a fun street cruiser.

I used AFR185 heads, an Air Gap manifold and a very mild cam (218/224 with 114 LSA and lift under 600) and on the engine dyno it was at 445hp at 6000 and had 430 ft/lbs of torque at 4400 and had more than 350 ft/pounds of torque from 2700 on up with a very flat torque curve.

With more cam, there is a lot more power to be had if you want it. But I wanted something that would be fun to drive, have good street manners and that would be compatible with a possible future swap to EFI or Webers. I've only got 100 miles on the engine so far and haven't really gotten on it hard yet since everything else in the car is still breaking in, but it does not feel like it is lacking for power. And if I ever want more power, I can do a cam swap or bolt on a Paxton.
 

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For similar money you can do a dart blocked 460 Windsor.
it might be 50 lb heavier but it will also have more power and torque.
i was enamored with the RY-45 for a while but realized it would cost double of a Kaase Boss 9
 

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For similar money you can do a dart blocked 460 Windsor.
it might be 50 lb heavier but it will also have more power and torque.
i was enamored with the RY-45 for a while but realized it would cost double of a Kaase Boss 9
Ford FR9, only $27k, needs a carb
 
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I gotta know. Who are the eight jokers who picked either of the "regular bore" options?
I was one :). I like the idea of the 363, but I also like the idea that you can rebuild that block many times over before it’s junk. I’m still on the fence if I want a 347 or 363. Woody will build mine as well.

Chris
 

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I was one :). I like the idea of the 363, but I also like the idea that you can rebuild that block many times over before it’s junk. I’m still on the fence if I want a 347 or 363. Woody will build mine as well.

Chris
Maximum bore on a Ford SHP block is 4.185. The 363 has a bore of 4.125 so you can probably get 2 rebuilds out of it
 

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Ford FR9, only $27k, needs a carb
And will make no low end power at all. The last cup engine (a couple of generations ago) I saw
personally on the Dyno didn’t wake up until +6k.
the entertaining thing about the RY-45 is that you can get 4.25” bores. Lots of big cube examples in the Trophy Truck series.
 

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Whats your hp and tq goal, and within what rpm range?
 

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Discussion Starter · #72 ·
Whats your hp and tq goal, and within what rpm range?
350 hp and 350 tq would get the job done "for now" and I realize that isn't asking for much these days. I'm probably closer to 400 hp now on my very problematic 331. 2500 - 7200 would be the rpm operating limits. I don't "need" a 363, but if its all the same money🤷‍♂️. I really just need a motor that I can install just once, not once every year.
 
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How about talkin yew ento a poor old nine ! The one in this video sounds like it has heavy rotatin stuff. this recording has a case-uh-dia of ..... mono ! oh no !


 

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Your issue is reliability. Not power.

Woody is the man. No question. I bought everything that he would sell me. But he wont build stock blocks. And the Dart SHP is a 70lbs penalty to you without delivering any additional useable power. They're great for a high RPM or boosted motor. But you're not looking for that. I wish Woody would build stock blocks. But he wont (and I understand - sort of - you can't buy an SHP now). So you need to find a local engine builder that will do a stock block and do it well. Go to a local drag event. Find the Ford guys. Ask them who they use. That's what I did.

350hp 350tq are easy numbers to make in a 289, let alone a 363.

You need to for real decide how much power you need. Without tubbing the car, I doubt you can put much more than 400 tq to the tire in an autox (cold tires - no burnout).

I'd find a local engine builder that you like and who will stand behind what they build. That's the critical issue for you. 331 or 363 ... you just need a motor that works reliably and isn't an anchor.

If you want more power, raise the compression to 11-12:1 (run race gas - this is a dedicated race car, right?), get a big ass cam, some proper heads (190+) and you'll be 500hp+ with the block you have. Sell the old too small heads.

The issue is, building anything right now is next to impossible. It took me months to get head gaskets. It's a total parts availability crap shoot. Tough time to start over.
 
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I bought a new 363 from Ford Motorsports in 2019:

I paid right at $7k, drop in ready with a 2 year warranty.
Next to the TKO 600 in my 65 coupe it was the single best decision I ever made regarding the car. Runs great, fired right up first key turn after priming the carb.
Dyno'd at 476hp at the back tires and I was still working carb jetting out.

Buy once, cry one.
 

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With the power you are looking for, I see no reason to really break the bank. But I also DO see a reason for just going with an aftermarket block, and thus a 363 is prudent in that case. You will be lucky to find a decent machine shop that will do a stock block right for less than $1000 in less than 12 months. Even the bad shops will charge you that much and take that long (or longer). My suggestion, given what you've stated as your goals? Here you go...


And hit up Ed Curtis or someone for the right cam.

Compression will be about 10.3:1. You'll have trouble getting as low as 350rwhp but your torque curve will be a straight line regardless. You won't have to wait for Woody to get Dart blocks in stock either. You'll still need to do all the valvetrain measurements and top end assembly but nobody will care about those jobs more than you do.
 

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You want to turn 7000rpm reliably in a road race situation, so you need an aftermarket block. Any stock 8.2 block is on borrowed time. Your not going to notice 70 pounds of weight low in the chassis directly over the front axle. If you are really concerned, cobra automotive will CNC lighten a dart block. This is done to the ford motorsport boss 302 blocks in Aus for V8 supercar racing. But these guys are trying to win national championships and spending 100K for an engine...

I would consider ZSR engines. I have heard on multiple occasions they do excellent ford work. If dart isn't available, get a world or ford motorsport block. The ford is lighter than a dart...
 

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As someone with a stock 5.0L roller block 331... who is considering a paxton.. I'd say aftermarket block and it all costs about the same when you go down that road for rotating assembly

. Part out the 331.. Get some decent heads on the 363 and have at it.

Seriously. AFR or TW in the 200-220 range and a good cam (I like my Howards roller) and it'll WAIL all day long and not complain.

I'm seriously regretting not doing the dart block myself..

I'm happy with the 331 now at 450 crank hp.. but I know if I add boost its on borrowed time. As someone else said. Pay once. Cry Once. I guess I have to do everything the hard way.
 

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Reading through this thread makes me wish I would have posted a pole asking if I should stroke to 427 rather than 408.....Seems my pole may have been leaning heavy to 427. I recall from my limited knowledge on the subject that I read decreased engine life the more you stroke it.
 
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