357w: would you do it again??

ras50gt · Dec 20, 2019

I'm leaning toward doing a 351w swap over a 347. Was considering going all out to a 408, but talked to a few people that said for a more street friendly car they probably would have done a 347 or 357w. I want to see if anyone else has experience on this. Did you build a short block and then realize you should have done it differently and or went too far with it?

I want to remain streetable and run on pump gas and at least keep up with newer cars. Figure the 351w will also give me room to grow in the future. My goal would be at least 450-500 hp. I had an 03 Cobra, which was my daily driver, around 480hp. I liked the power level and it could hang with a lot of cars. I do have a supercharger to install or sell depending on the route I go. It's a paxton sl1220. Too small for a 357w?

a91what · Dec 20, 2019

Lets talk about supporting parts...
as an example I have built a 393w that should make somewhere around 450-500hp easily and be tame enough the wife could go get groceries in it. The way the car idles and cruise characteristics are determined mostly by cam selection.
-cam is mildish mid 230* duration with 114*LSA and 575lift. very streetable and on the small side for a 393w
-heads are budget minded ProMaxx 190cc I chose these on a recommendation, some of my customers i tune for have made great power with these.
- intake choice will vary by build I am using a holley hi ram on this one.
I am hoping for a nice flat torque curve that exceeds 400fllbs from 2200-6200 rpm this will make the car fun to drive. The cam choice will idle easily at 600rpm if i want it too and will have a slightly aggressive tone at idle. Car should get great fuel mileage as well

bottom line the increased displacement will make power production easy and will make a cam act smaller than it is making idle and cruise characteristics smooth. I would never spend money on a short-block or bottom end parts and not stroke the engine.

95BlueStallion · Dec 20, 2019

What he said.

Go 408 with a custom cam made to be well mannered. Cam gurus know how to make em anyway you want.

My 347 is a bit grumpy because of my cam. I bought it as a whole prebuilt engine, so for me it just is what it is for now. But it’s not because of the stroke.

Steel1 · Dec 20, 2019

Been very happy with my 393w, my cam is a little aggressive but it's just a weekend cruiser.
I would definitely do it again, imo it was a fairly straight forward swap.

JD1964 · Dec 20, 2019

393 with mild cam. Yes to the blower for serious top end power. Done right, you should be able to put well over 500hp to the wheel and still be pump gas grocery getter attitude. Limit the compression so you can reduce complications with boost.

ras50gt · Dec 20, 2019

My plan was trick flow 11r heads 190 or 205. Can you suggest a mild cam?

So you think the Paxton 1220sl will perform well? Or should I sell it and eventually go with a different blower or turbo?

My thinking is 357 or 393 with a supercharger over going n/a 408.

General karthief · Dec 20, 2019

393 with a BDS 471
You'll have to cut a hole in the hood though.

Ragtop50 · Dec 21, 2019

I am in the same situation now. Considering a 357w for various reasons, but mainly because if I go 408, everything else will need to be changed as well to support it (exhaust system, transmission, way bigger heads). I have a 100% street car that gets driven maybe 750 miles a year at most.
I too plan to run boost (supercharger) so I think a 357w would be best of both worlds.
I am also trying to keep this under a stock hood, and with such intake limitations in doing so I would be choking a 408.

Steel1 · Dec 21, 2019

I had a couple of different supercharged set-ups on my original 302w, all probably in the 400-425 hp
range, they were a lot of fun but came with their own set of difficulties.
When I built my 393w I was looking to make similar power but do it n/a, thus eliminating some of the
issues that go along with supercharging.
From my butt dyno I can tell I've pulled it off and then some.
We all know power is addictive and I always liked the sound of a whining s/c, but for now I'm satisfied
with my set-up.

ras50gt · Dec 21, 2019

Ragtop50 said:
I am in the same situation now. Considering a 357w for various reasons, but mainly because if I go 408, everything else will need to be changed as well to support it (exhaust system, transmission, way bigger heads). I have a 100% street car that gets driven maybe 750 miles a year at most.
I too plan to run boost (supercharger) so I think a 357w would be best of both worlds.
I am also trying to keep this under a stock hood, and with such intake limitations in doing so I would be choking a 408.

Yeah, I'm thinking a 357 or 393 will provide plenty of power and fun yet still be streetable. I worry that a 408 and supporting mods will quickly get to 550+ hp and be more of a track car.

ras50gt · Dec 21, 2019

Steel1 said:
I had a couple of different supercharged set-ups on my original 302w, all probably in the 400-425 hp
range, they were a lot of fun but came with their own set of difficulties.
When I built my 393w I was looking to make similar power but do it n/a, thus eliminating some of the
issues that go along with supercharging.
From my butt dyno I can tell I've pulled it off and then some.
We all know power is addictive and I always liked the sound of a whining s/c, but for now I'm satisfied
with my set-up.

I once had my mind set on a 331 with the paxton 1220. Then I was thinking sell the paxton for a kenne bell. Now I see the advantages of going 351w. Decisions decisions.

Mike62 · Dec 22, 2019

The old saleen s351r was a mild 351w with a vortech, they made around 480hp. That should be reliable for years.

ras50gt · Jan 4, 2020

ttt, added a poll

revhead347 · Jan 4, 2020

347 every Saturday and twice on Sunday. I have a friend that committed to a 351 years ago, and I went with a 347. My nitrous 347 absolutely kills his turbo 351. Here's why, the 347 was essentially a drop in. It meant less time, and a lot less money. The 351 swap nickel and dimes you to death on swap parts; special engine mounts, different headers, different distributor, etc, on and on. That means you have less money to spend on parts that actually do more, like a better axle, good clutch, really good tune. In fact, in the real world, you can put an aftermarket block 347 in for less money than a stock block 351w swap. I've priced it out several times. Now I'm not saying there isn't a perfect methodical build sheet to put a 351w in for less money, what I'm saying is that in the real world, you get hit with all kinds of unexpected costs. A 4 bolt main 8.2" (302) block is going to give you way more room to grow than a stock 2 bolt 351w engine.

Kurt

ras50gt · Feb 22, 2020

I feel like the more research I do, the more I change my mind. I spoke with someone at a car show recently that had a 351w and he said if he had to do it over again he probably would just do a mild 331/347. Main reason, like Kurt mentioned was just the little nickel and dime items and figuring out what parts fit. Even now after all is done, if something needs to be replaced or upgraded, it's more of a headache to do. Obviosuly he got bigger heads, etc but he said before he knew it he was over 500hp which may not sound like a negative but his goal was similar to mine (450hp, more streetable, not necessarily a daily driver but could be.)

revhead347 said:
347 every Saturday and twice on Sunday. I have a friend that committed to a 351 years ago, and I went with a 347. My nitrous 347 absolutely kills his turbo 351. Here's why, the 347 was essentially a drop in. It meant less time, and a lot less money. The 351 swap nickel and dimes you to death on swap parts; special engine mounts, different headers, different distributor, etc, on and on. That means you have less money to spend on parts that actually do more, like a better axle, good clutch, really good tune. In fact, in the real world, you can put an aftermarket block 347 in for less money than a stock block 351w swap. I've priced it out several times. Now I'm not saying there isn't a perfect methodical build sheet to put a 351w in for less money, what I'm saying is that in the real world, you get hit with all kinds of unexpected costs. A 4 bolt main 8.2" (302) block is going to give you way more room to grow than a stock 2 bolt 351w engine.

Kurt

Steel1 · Feb 23, 2020

Any engine build is going to nickle and dime you , prepare yourself for that going in.

Ragtop50 · Feb 23, 2020

If you are targeting around 450 HP, I absolutely would stay 8.2 deck and go with a 331/347. And actually, due to a heavier rotating mass, a 347 may perform better than a 351/357 depending on the setup. Close to stock, I would say definitely that would be the case.
Thing is, you have to be honest with yourself about that really being your goal and limit. Most people end up wanting more.

2000xp8 · Feb 23, 2020

Use a dart 302 block, if needed, I think you could goto a 363.
Especially if you are going to do a supercharger.
I see no point in making the swap more expensive, difficult and heavier with a 351.
A dart block is superior to any 2 bolt 351.

But if you want the car to run and feel like a terminator, there is only one way to really do that...

Ragtop50 · Feb 23, 2020

2000xp8 said:
Use a dart 302 block, if needed, I think you could goto a 363.
Especially if you are going to do a supercharger.
I see no point in making the swap more expensive, difficult and heavier with a 351.
A dart block is superior to any 2 bolt 351.

But if you want the car to run and feel like a terminator, there is only one way to really do that...

Problem there is a dart block is going to make it a good bit more expensive than a 351. That's one main reason people go the 9.5 deck route, can be a good bit cheaper than a dart block and of course the ability to really go up in cubic inches. There are plenty of 351/357s running around putting down 650/700+ hp on a stock block, it can take it.
Also, a dart block will be heavier than a stock block 8.2 deck.
Dart block is great, but it will be more expensive.

But keep in mind, you may have issues installing your supercharger on a 351 without a proper or modified bracket.

2000xp8 · Feb 23, 2020

While in some situations, depending on how you acquire the 351, it may come out cheaper than a dart, there is still all the swap parts you have to pay for.
There are no swap parts for a 347. You could literally bolt everything you own back on it.

I'd be curious on what everyone around here makes with their 351 builds, either quarter mile or rearwheel dyno.
Over the years other than on race cars, i've seen little proof it's worth the effort.

357w: would you do it again??

Which short block? Street car, no track. Goal 450-500hp, TF 11r heads.

357w

393w

408w

347

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My assy trans to myself

Mustang Master

there is enough sticking out to grab on to

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wonder how much it would cost to ship you a pair

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Mustang Master

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Apparently my ex-husband made that mistake.

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Mustang Master

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