351/408 analysis paralysis UPDATE : 347 it is then ! LOL

[HoosierDaddy]

If your going to stroke something, why waste ANY money on a 347? For the same money you could have a 408 that would kick any 347's butt any day of the week! Besides a stock 351 is still bigger, and can still make better torque where your Bronco will ACTUALLY use it... If your talking about going down the 1/4 mile then things would be different.

Post #15 , you'll see my reasoning. I was of the same mind for a long time.

After learning MUCH during this quest , I have a hard time believeing there is a big difference in performance between the two (347 vs 351). Main physical difference is the 347 maxes out the block whereas the 351 has another 57+ cubes to go.
I am quite sure I do not need those extra fifty cubes to accomplish what I want and the extra size of the 351 motor creates a boat load of issues I do not want.

 

[Broncobowsher]

I understand the desire to keep body lift down and a stock hood. But I think it can be done with the 351 if you are a little creative. I feel the intake can be shortened a little by milling the mating surfaces between upper and lower intakes, not sure how much. I remember researching a mustang build once that did this to keep a stock hood. And build your own motor mounts to lower the engine a little more.

You ask an engine builder if they can build something for you, why YES THEY CAN! The builder would be an idiot to scare away a potential customer. You want a 347, sure I can build you one. I will make a lot more profit off that then doing another 351. I look at it this way, Ford is a car company and car companies tend to do things the ceap way if possible. The 302 already existed (or at least a good way through the development cycle) when they decided to make an even larger engine. If Ford could have gotten away with using the basic 302 block then they would have. The limitations were reached when the 289 was stroked into the 302, so they went all out and did things right and properly designed a stroker 302 and made the 351. Now you have enough deck height for some proper rods. But they were still cheap about it, just modified the 302 production a little to pull it off. Same cam, lifter, front of engine, etc. So they cheaped out where they could get away with it, but where it really counts on a stroker they did things right.

And 408 isn't the upper limit on a 351 based stroker. I know that a stock block can go to 427, but it is a lot tougher fitting that kit together (clearances get tight). And if you want to try a 4.125" bore on an aftermarket siamesed block then you can hit 454 inches. By that point the GT40 intake isn't going to be enough...

 

[fungus]

I recently just went through this same dilema however my end goals for my rig are much different which swayed me towards the 5.8. I'm building a rig for the Rubicon with FW axles, doubler, 40" sized tires etc. I was given a mustang 5.0 and was going to put a 347 kit in it to get the torque I wanted to turn said tires in the rocks. I ended up finding a full roller '94 5.8L for $250 and quickly changed gears. I didn't feel comfy maxing out a 5.0 block in such a trail rig. I figured the 5.8 build would leave me more options down the road for increased power should I determine I want it. All the parts I'd acquired for the 347 bolt right on to my 5.8 build as well. PLUS, I'm running about 30% the cost with the 5.8 vs the 347 when you figure purchase+ shipping of a 347 kit to Hawaii (another big decision point). Only thing I needed that I didn't have was a Lightning lower and I was able to source one of those cheap enough & had it shipped out here from another EB'er. Now, I'll have a very nicely built 351 & if I find it's not enough for what I need down the road I'll look into stroking it (but doubt I'll need to).

Had I been building a rig with your described usage, not had to deal with expansive shipping costs & was sitting on an explorer 5.0 & didn't have a 5.8 sitting next to it I'd probably go with the 347. Keep in mind there is also a 331 kit that alot of guys seem to like as well and leave you a little more room in the block assembly. Just another option to look at for you.

I've since taken the stang block I was given, honed it out myself and cleaned it up real good, new bearings & rings, put the fresh set of GT40 heads I had on it w/ Ford Racing 1.6 ratio pedestal mount roller rockers, explorer GT40 efi and am waiting to drop it into my '69 as a complete EFI swap vice retrofitting the EFI on my '69 302. I think it'll make a REAL nice powerplant for the '69 that's rollin' on 33s and might see 35s in the future but nothing larger. Stock bore, crank, rods, pistons & cam & I built it for less than $1K total investment on my back porch.

 

[360 4V]

Do you want to build a 347 stroker today and build a 427 stroker tomorrow or do you want to stroke a 351W the first tome around and be done with it? Either is an acceptable answer.

 

[KyleQ]

Horsepower is a disease, you are always going to want more. I'm a little sad to see that you are building a 347 when a 351W is a much better option compared to stroking a 302 - as you said, sam cam, same heads, etc etc.

Regardless, I like your cam choice - I built a 351W with similar specs (TFS 185s and 10.5:1) and used a bit bigger of a cam, but LSA is still 112, so it will idle great. Comp 35-518-8

 

[rjrobin2002]

This is the cam in my 347 that they previous owner built and mine drives great with 35's. I can even start out on 2nd gear without any problems. My motor is extremely fast revving like a motorcycle and fun to drive. It is not a torque monster though and still likes 2000+rpm's.

 

[HoosierDaddy]

This is the cam in my 347 that they previous owner built and mine drives great with 35's. I can even start out on 2nd gear without any problems.

It is not a torque monster though and still likes 2000+rpm's.

Hmmm, I'm confused ? The second sentence contradicts the first , I think ... When does it need 2000+ rpm , for what conditions ?

Also , do you know what gears you are running?

That cam is on my short list for sure.

 

[fungus]

Here's the cam I put in my 5.8 for the crawler. I've got some bud's on the Norcal board that run this cam in their 5.0s (both mild & a couple 347 guys) and LOVE it.

http://www.summitracing.com/parts/CCA-35-308-8

 

[rjrobin2002]

Hmmm, I'm confused ? The second sentence contradicts the first , I think ... When does it need 2000+ rpm , for what conditions ?

Also , do you know what gears you are running?

That cam is on my short list for sure.

I am just saying my motor is at its prime when revved up around 2-3000 RPM's. I don't feel much torque at idle and have to give it some gas before letting the clutch out. I have 4.56 gears.
Like I said, it drives great and will haul ass. I would be willing to race anyone on the site with a 351 and think I could take them.

 

[AZ69EB]

That sounds like a challenge. Any takers? If so, get video for us out of Towner’s.