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Hey I have never riden in a mustang with a 351W. How much better is the performance? Is the bigger motor worth the sacrifice of the extra space? Lets say I am going to mostly MILD on a 351W is it that much of a performance boost?
 

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Hey I have never riden in a mustang with a 351W. How much better is the performance? Is the bigger motor worth the sacrifice of the extra space? Lets say I am going to mostly MILD on a 351W is it that much of a performance boost?


only worth it if you are going stroker to 393 or above since a 302 can commonly expand to 347.....
 

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A 351W block has the advantage of more displacement. I have seen 427ci stroker kits. It will be heavier than the 289/302 but you can lighten it up plenty with an aluminum top end. If I remember correctly, a 302 block reaches its limit somewhere in the 500-600hp range. A 351 has much more room. With today's technology, "mild" can still get you 400hp easily. It depends on how much you want to spend. Since you are doing body work on the car now, consider strengthening the body to handle a good amount of horsepower. Torque boxes, sub frame connectors, convertible inner rockers, once piece seats pan...there are plenty of options.

Do a search for the 302 / 351 debate. It's probably been discussed many times in this forum's history.

http://forums.vintage-mustang.com/vintage-mustang-forum/598876-289-302-351-a.html

I chose to go with a 351W based build for my '65 coupe. It has a certain allure. The possibility of a 408W stroker in my Mustang seems irresistible.
 

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Back many years ago we installed a bone stock 1969 351W (4v) from a Mach 1 into my 1965 Falcon Futura factory 4 speed car.
This engine was factory-rated at 290hp, which I think was way low.
This little Falcon with a 3.50.1 rear end was VERY fast right out the door, we beat everyone we raced that had 289s and 302s and when we showed then the engine in the Falcon they couldn't figure out what made it so fast-we used standard 289 exhaust manifolds because the 351s wouldn't fit and there were no swap headders made yet.
 

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Discussion Starter #5
Right now I have good running 302 I bought for 600 bucks sitting in the corner of my garage. But i would not mind looking at a 351W. It seems sort of different really I don't want any more than about 350HP something like the 69 351W 4V engine seems nice but the compresion seem too high to me... Mild cam decent heads aluminum intake...that sort of stuff.
 

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Vipex hit the nail on the head. It's a tight fit and you can do very well with a 302 or 5.0 better yet. Stroke it for more cubes and you can still have a good selection available to you for headers.
Also, is this for the GT you just got? If so, the 302 will look a little more normal... Just my opinion.
Also, isn't there a Ford crate 306 putting out 350HP? just drop one of those in and be done!
 

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I would stick with the 302, if you're only looking 350H. My 306 dynoed at 348 RWHP with Windsor Jr heads, Performer RPM, 600 Eddy, and a little magical cam.
Not to mention a lighter engine with lots of available parts!
 

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I have tried both and how you build it is more important than the 302 vs 351 argument. If you are sure you only want 350HP stick with the 302.

Every time I build a new engine I think, man this is going to be quick and by the end of the summer wish I had another 100HP.
 

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As you can see, I already have a 351 (well, stroked to 377) in my 66. Runs great, but:
Special headers, special radiator (haven't known anyone who did this not have a cooling problem) the inlet/outlets are different on the 351, other issues.
At the time, they weren't stroking the 302's. If I knew they were to come out with them, I would have waited and put in a stroked 302.
 

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if your not going to build an engine then put the 351 in. if your going to build a stroker then stroke the 351. if you want a low rpm daily driver with over 500 hp stroke the 351 to 392+ c.i.. if you want a real high rpm (9000+) engine thats not very streetable then build a boss 302. theres no substitue for c.i. if there was then top fuel dragsters would be running the same e.t. with 200c.i. i like the stroked W. its an easy swap in a 65-66 and hooker makes a real nice set of headers that work with a toploader 4 speed. you can put a 4 row radiator from a 69 or 70 (depending on water pump inlet) in the 65-66. i have done this swap and it E-A-S-Y ! the 3.5" stroke of the W makes more torque. i have heard that a 347 will beat a 351W at the dragstrip everytime but that was 347 vs 351. i never heard anyone say a 347 will beat a 392-427W at the drag strip !!!
 

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As you can see, I already have a 351 (well, stroked to 377) in my 66. Runs great, but:
Special headers, special radiator (haven't known anyone who did this not have a cooling problem) the inlet/outlets are different on the 351, other issues.
just currious, what other issues ? also when i built hot 289's back in the 70's and 80's i always needed a bigger radiator for the xtra hp.
 

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I'm using a stock sized radiator with no cooling issues, but we rarely see 90-100 F days up here.

I took my radiator to the shop down the street and they upgraded the core with a very dense core (I can't recall how many tubes / inch). The rad guy claimed it would easily cool a 400c.i. engine. Looks stock and works great, no cooling issues.
 

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I have a '68 Convert that has a '69 351W. The car presently has headers and I would like to go back to stock exhaust manifolds & stock exhaust.

Are there different applications for the stock 351W exhaust manifolds? If so, which should I use?

I want to use an off-the-rack, stock exhaust system that bolts up, right out of the box, but don't know what year to use for my application. 351W's were never offered in '68, but were in '69.

Are the engine bay dimensions the same for both '68 & '68 converts?

Anything else I should know?

Thanks
 

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Hey I have never riden in a mustang with a 351W. How much better is the performance? Is the bigger motor worth the sacrifice of the extra space? Lets say I am going to mostly MILD on a 351W is it that much of a performance boost?
What are you going to do with the car? Daily driver, autocross, drag race? What manners you looking for from the motor (are you willing to put up with crappy idle? Remember the 351 is going to be heavier but it will allow you to stroke it for much more HP, great in a drag race maybe so much as a daily driver or on a road course. If you're happy with 400hp then go with a 302. Lighten it up even more with a set of AFRs or Trickflows, go full roller on the valve train and with the right cam you'll be there.

Expect a lot of bad advice, even from builders. I have yet to get a recommendation on a cam that "worked". Most people usually recommend one that is TOO BIG. Sure it makes gobs of power on the dyno but put it into the car and its manners are horrible. Most importantly, build it reliable. Cut corners and you'll spend all your time pushing it home and fixing it.

One thing I forgot, if you start making big power with lots of torque expect the need to upgrade the trans and rear.
 
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