66 Coupe 302 vs 351W

[Bullitt]

My goal is for a nice drive with a good bump in power. Not a daily driver but definately to be driven.

No one has asked what your budget is or what power you're interested in making... so what is it?

You can build a 350 to 400HP 302 that'll be a kick in the pants and get decent mileage for not too much $. Don't need to fiddle with strokers and all that.

Just might take a step back and decide what you really want.

 

[js66coupe]

My concerns, which may or may not be legitimate, with going with a 351W (stroked) are the following: The added weight. I don't want poor handling in the corners and I've heard the 351W is 200lbs more than the 302 but that doesn't seem right. Even if I go with aluminum heads and intake, that will still weigh more than a 302 with aluminum heads and intake. The added torque. No sense in over powering the car if a stroked 302 will work. The transmission. I want to use a C4 over a C6 (C6 is heavier). I would think a built C4 can handle a warmed over motor. Room in the engine bay. I've got enough headaches working on a late model car with no room in the engine bay, don't want a new one. The 302 is a nice size for a 66. If I had a 67+ Mustang, I'd def. go with the 351 as the 67s on up are wider. 66, just not sure yet.

The pluses, to me, for a 351W are the stronger block and the ability to get more torque and horsepower out of the engine while making it more driveable. The bigger cubed engines will smooth out the wilder cams where a smaller cubed engine will have more lope. I want some extra power but without serious lope.

Since I want to build a new HR motor, there's no reason not to stroke it. I'll be using a new crank, might as well stroke it. (I won't be messing with the original block.)

As far as budget, I'm not building a racing motor but I do plan on using better quality parts. Engine will run a carb rather than fuel inj. No forced induction, maybe a small hit of N20, maybe not. I hate giving a dollar figure but having done this once before, I know what to expect.

Right now, I'm leaning 351W but we'll see.

 

[rebel65]

Musta been a function of your intake, because you can get the hood closed on a 351 in a 65.

Yep. A buddy has a 65 with a 351W and it has the stock hood. The previous poster that needed a new hood has a performer rpm air gar intake which sits kind of tall. It also depends what kind of air cleaner you have. There are low profile air cleaners that will help and that will still flow plenty good. I used to have acar that I had an Edelbrock Pro Flow air cleaner like the picture below. It provides good hood clearance and still flows plenty.

never said it was impossible heh, it is definatly the specific engine combination i picked and as i said i liked the new hood anyway got to save a couple pounds with fiberglass. impo i like it but that is why it's my opinion i guess .

you address the weight again, and i know they don't weigh 200 lbs different, i just know they don't, the [/B]blocks[/B] are not that much different, and that is where the weight means something, right, what is a little wider intake going to weigh in at? 10 lbs more if it's aluminum? less? Of course i haven't weight both. darn it i should have lol now i feel like stripping my old 289 and go buy a 351 block and weigh em both. I've never seen someone say they weigh more than 100 lbs different.

the size difference is almost nothing, about 1 inch taller and i think ~2" wider? sure the big 'ol headers don't fit quite as well as my old little ittly bitty shorties did, but a little hammering on one shock tower was enough to get clearance, i can take out my spark plugs just as difficultly as it used to be. lol

347 vs say 383, you can get the same power out of them, but the difference will be in the cam, and RPM where the power is in. the 347 would get it's max HP at an RPM the 383 can't even get to, now personally i don't have an INCREDIBLY streetable cam. but when the car is feeling in a good mood i never have a problem tooling around town. but if i start looking at other cars, she makes idle rough : ).

hers a side by side of my 289 i just found on an old computer hah, and my new engine the angle is a little different and the 351 is taken a liiiiitle bit closer to the car, but they are pretty close.

 

[109jb]

The 351W is about 55 pounds heavier than a 302. That weight is mainly in the block and crank. The 351W weighs 530 lbs. The 302 weighs 475 lbs. All of these weights are for the long block with iron heads.

302 specs here

351W specs here

Also, a 351 fits the bay without modifications, but you can gain some clearance on the sides by just notching the shock towers. You can still use the same suspension and don't have to go to a coil-over or anything like that. Here is a description of shock tower notching.

 

[dennis112]

rebel65 289:

My "sleeper" 393w in a 65':

A 351w does fit OK in the 65/66 chassis with minor mods to the shock towers to accommodate the header tubes. The exhaust is the worst part of this swap due to the narrow engine compartment.

It is not worth swapping a 351w into these cars unless you build a big powerful stroker (408ci or more.) You can get the same (or even better) overall performance out of the lighter weight, lighter rotating assembly 347. The 347 will be easier to work on and you have a distinct advantage as far as headers go. The 302 based motors will also be easier on the drivetrain than the high torque windsors.

If you still want to go the 351w route, it will fit under the stock hood if you use a Stealth or regular RPM intake and a drop based air filter. If you want to get really tricky, you can even hide a modified Vic Jr intake under the hood and yet still use a nice sized air cleaner as I have above. That is a track pic from last week after a drag run and I run it as you see it.

 

[blown65]

Either way is good for me. For a street setup I would def go the stroker 351 route though. 393 or a 408. Race stuff I would prob go back to a 347 mainly because of header clearance issues. So many advantages of each its really going to be decided on what a person is going to do.

 

[2+2GT]

If you get headers made for the 351W in the 64-66, you won't have to hammer anything.

No matter what you do to a 351W to lighten it, the 302 with the same mods will always be lighter.

Of course, people used to complain about the "front heavy" 428 Mustang, but the Fox-body 5.0 Mustang had the same front/rear weight distribution, and a reputation for good handling. Mostly it depends on suspension setup.

 

[72 fastback]

The 351w is about 65 lbs heavier. My cast iron heads complete with guide plates and studs were 48 lbs and my edelbrocks heads were 28 lbs complete. You will never notice 25 lbs on your front end.

 

[rebel65]

definatly, if matters where you wants your power. hope we helped lol. heck, next motor i build will probably be a 331 turbo lol.

 

[109jb]

Below is an example of how much room is gained for working on a 351W when you notch your shock towers. This cost me $14 for 3/16" steel plate to do this and took about 3 hours total.

 

[YourBaby'sDaddy]

Below is an example of how much room is gained for working on a 351W when you notch your shock towers. This cost me $14 for 3/16" steel plate to do this and took about 3 hours total.

What car is this in?

 

[109jb]

What car is this in?

1970 mustang