351w questions

my67stang

New Member
Aug 22, 2005
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HI. I am thinking about putting a 351w into m '67 mustang coupe since it is an easy swap with the stock 289. Anyway the guy I am buying it from says that the engine proabably has around 400 horsepower. I was wondering what mods I need to do to the rest of the car to handle that power. Can the stock c4 handle it? Do I need to upgrade to a 9" rear end. I am already planning on upgrading to front disc brakes. Anyway if you have an opinion let me hear it. Thanks
 
If the engine is a legit 400 hp engine and you plan on driving it aggressively a 9" would be recomended. I don't think a used stock C-4 would hold up under that much power. A C4 can be rebuilt to handle more power than that. You could run the C4 until you trash it and then rebuild it or rebuild it right away. Your choice.
 
if you are not going to use slicks, then the stock driveline, as long as it is for the 289, can handle the power, though durability will be compromised. when the parts break, you can upgrade them as you replace them.
 
The little C4 is stronger than most folks give it credit for, and for the price of a B&M/TCI built AOD you can hold 700+hp with a C4.

But the missing gear really sucks for driving the public roads.
 
Well, my first thought is 9 times out of 10, when someone "says" that they have 400 horsepower..........it is usually 300............get the specs on the cam, heads, etc, first before you start budgeting money towards upgrades.........otherwise just put in a shift kit and you'll probably be fine............

Chris Barton


my67stang said:
HI. I am thinking about putting a 351w into m '67 mustang coupe since it is an easy swap with the stock 289. Anyway the guy I am buying it from says that the engine proabably has around 400 horsepower. I was wondering what mods I need to do to the rest of the car to handle that power. Can the stock c4 handle it? Do I need to upgrade to a 9" rear end. I am already planning on upgrading to front disc brakes. Anyway if you have an opinion let me hear it. Thanks
 
Cbarton said:
Well, my first thought is 9 times out of 10, when someone "says" that they have 400 horsepower..........it is usually 300
9 out of 10? Really? I guess you've been around a lot of younger enthusiasts then :D

On a more serious note, when I hear the 400hp number and find they have a N/A-289/302 I am also skeptical, but for folks with the big windsors I am less so, 400 is pretty easy and cheap to get even without stroking the 351W. When you get to FE/C/385 owners it is even easier. But when the claim is made and they know nothing about the specs as you mentioned my skepticism meter goes off too.
 
Yeah, I agree.........I am 42 years old, so I go back to the day when 400 hp was the 'Magic" number. EVERYBODY said their hot rod had 400 hp. Of course then when dynos became readily available.........most of those guys couldn't back it up. You are right about the 289/302's tho....I have seen so many examples of someone who builds a 302 with intake, allum heads, hot cam and intake carb only to be disapointed with sub 300hp on the dyno........SOUNDS like 400hp tho..........


Chris


Edbert said:
9 out of 10? Really? I guess you've been around a lot of younger enthusiasts then :D

On a more serious note, when I hear the 400hp number and find they have a N/A-289/302 I am also skeptical, but for folks with the big windsors I am less so, 400 is pretty easy and cheap to get even without stroking the 351W. When you get to FE/C/385 owners it is even easier. But when the claim is made and they know nothing about the specs as you mentioned my skepticism meter goes off too.
 
Other things

Besides tranny, and rear. If you are going to flog that motor you'll want traction bars of some kind, as well as subframe connectors, better shocks, better tires.

As far as the trans goes, you'd be surprised how much the stock C4 will handle, but you want to make sure and get the specs for the Cam, Intake and heads so that you can properly size the Tourque convertor. Depending on where and how the tourque curve looks will determine the stall speed of the convertor.
You don't have to change the convertor at that HP level, but it make for a much better driver.

I'm still breaking in my new 351w that I built for my 66. I put a TCI street fighter c4 in with a Jegs 2500 stall convertor. It also has CE traction bars and subframe connectors. I can cruise around just fine, even idle at a light, and when I nail it, it chirps the tires shifting in to 2nd, and maybe in third but by then I going to friggin fast to pay attention to whether the tires chirp or not.

Brent