Fox 351 / 408 Stroker Upgrade Or Start Fresh

buckwild880024

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Jun 8, 2008
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i currently have a 351w 30 over that i am lookingto make some changes to and get more power out of. looking for was to get the most bang for my buck. getting a great deal on a stroker crank from a budy of mine. he bought it and is now changing to the cyote motor. some research i have done says... cks-w351ee crank and stock length rods should get me 408. i have theperformer rmp cam/intake/ ect.
just trying to find out if just replacing the crank is going to work and if i change to the x303 cam am i going to have clearanceissues
 
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Increasing displacement will not yield the same bang for the buck that a HCI will. Matter of fact, Depending on your current head, building a bigger engine may exceed the heads ability to feed the new bottom end.

If I was looking for power, (and wanted to keep the engine N/A), I'd put a great head/cam/intake on a stock displacement bottom end before I'd bore and stroke it ( unless the engine was worn out)

**just re read your post. Replacing your stock crank w/ that stroker will require a piston change. The pin on the stroker piston is higher than where it is located on the stock piston. If you change the crank, you're gonna have to change the entire recip Assy.
 
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Motor is not worn at all. Built about 10 years ago and drove for about 5 then had kids and the rest is probably self explanatory. Drive the car about 6 times at the track. Other than that she looks great on the garage. Kids and wife soak up most of my disposable car money. So looking for ways to increase power cheap.. My budy who just has cash to burn has the crank and is offering to sell for his coyote build.
 
Like I said then. You cannot just replace the crank. Even though the rods are the same length, the difference in the stroke is made up by raising the pin in the piston. You will need a set of pistons for the application.
 
Build a 393...pretty simple...stroker crank and 302 pistons...cheap bang for the buck. Just my .02
 
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With out trying to sound like a @$#& if I were to just change the crank would I have a 393 rather than 408?

No, you need 302 pistons, stock length 351 rods, and 3.85" crank. Summit sells the cranks for 399 bucks, everything else you can scrounge. It's what I'm going to do for my next project.
 
Your money is better spent on heads and intake. Even with a free crank, you are looking at some machine work costs. With all of it, you might move your peak power down 500rpm, but likely wouldn't gain any more. Throw some Trick Flow 11R heads, cam and a better intake on there, and you could squeeze out an extra 100hp for a little more money than a new bottom end.

Kurt
 
Huh? What heads are you running? What's your budget for modifications/upgrades? What is your intended use of car? Strip,street,combination of the two? Is this a roller cam block or an older flat tappet cam?
 
Stock heads that have some work done to them. I have moved towards just track over the years because I don't drive the car anyway. Lol... Limited time. Might see some street time in the summer but I honestly could say maybe 3 weekends.
Non roller block 78.
Currently.. Performer rpm intake and cam.
Msd 6al, t5 trans, 373 gear. BBK equal length headers 2.5" exhaust no cats. 750 Holley dp. 1.7 rockets. Aprox 10.1 comp. Last I knew when I built the motor.
Budget .... Tis the season to skim off the top... :banana::banana:Minimal looking for bang for the buck. 3 kids wife
 
Budget .... Tis the season to skim off the top... :banana::banana:Minimal looking for bang for the buck. 3 kids wife

With that said, what is your realistic budget for going fast?

What I think the guys are saying is that to get the best HP potential you may need to go with an aftermarket set of aluminum heads and better cam. Sticking with the parts you have right now and adding more CID while breathing through stock worked over heads may not net you much HP gain for the money invested.
 
You would see the biggest bang for the buck swapping over to some good aluminum heads. I prefer the trick flow 11r's but Afr makes a superior product also. Even some used 170cc tfs-afr 185's would be a good option. With no other changes(other than proper valvetrain,gaskets etc) you would see a significant power increase. Those stock heads are such a restriction(even if they are worked on) that you would probably see 25-50hp!

To swap over to a roller cam you'll need to buy some link bar lifters(minimum of 350$ just for lifters-no cam). Do you already have an X cam? If not I'd recommend a better option from any of the other cam companies. Like comp cams,Lunati,bullet etc. You can check their websites out and fill out a cam recommendation form and they will give you a better option.

With the proper cam,heads,valvetrain,etc you could pick up 100+ hp over your current combo. If you want to go stroker you'll need to do these things anyway to utilize the extra cubic inches. The head/cam option is going to cost a minimum of 1500$(if you find some used parts) and if purchasing new at least 3k. A 408 shortblock build is going to cost at least 3k. All told you would be looking at 5-7k
 
Thanks... Dont have the crank that is why I am trying to research before I jump in and find myself stuck. I was a idea.
Sounds like heads and cam are going to be the current logical move then I can stroke later.
I will look into those prions and see what makes sence
 
So, i have been looking into all the ffed back and information. Might have a good deal on n351 heads.... thoughts
You building a circle track car? You're not going to see a huge increase from an old set of Sportsmans. Not to mention you'll want a particular piston set up for best performance. Great cylinder head suggestions have already been given. You should listen to them. If the cost of a good aluminum head has you shying away, then perhaps you should re-evaluate your priorities. While you're at it....you should really look into alternatives to the X-303 as well. Much better camshafts choices on the market now since Fords alphabet line-up was introduced. Speed costs money....how fast do you want to go!
 
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