AdderMk2

I have seen many posts on this forum that pertain to " hey, how much does it cost to stroke out my 302?"

All I can ever think of is, Why would you bother? You can do a FULL rebuild plus h/c/i combo on a 351w and have 100+ more HP and torque. I see guys on here like Randy, with the 408, running 400+ hp and everyone is always trying to get 400 out of a 302 based block. My guess is that Randy;s 408 is running lower compression then a typical 302, a mild cam, and a nice set of heads. Do you guys even realize that its possible to get 500-600+ hp out of a 351w based motor?

I just read a post about someone who wanted to build a 347 stroker and was wondering about prices of rotating assemblies.
https://mustangforums.com/m_1908590/tm.htm

Does this person realize that if he has a machine shop do the work and build his motor, its going to cost him another 3k atleast???
Start off with a 351w and have a reliable, rev happy, non-oil burning, STRONG block. Oh and heres a news flash... with the exception of your headers... EVERYTHING IS INTERCHANGEABLE....


I really thin more people on this forum need to pull their heads from their rear ends when it comes to doing big time motor work. Save the money, get a 351w, and thank me later.

vristang

LOL

Well, more than just the headers have to be replaced. There is a lot of planning that needs to go into the conversion.

I will be the last one to disagree with your argument, but that much effor is not for everyone.

Just like some guys want to take the car to a dyno for a tune, and others spend countless hours toiling away with a tweecer.

Just dropping in a fresh motor has its appeal. I could definately appreciate that kind of EASY engine change, after having gone through the 351w swap.

I love the 351w, but it isn't for everyone I guess.

jason

PX429

Plus some of us live in Cali

AdderMk2

From what I have gathered, you dont need to change the alternator bracket, however i could be wrong. My argument is not that its alot of work (which it really isnt) but i just find it silly that people will spend 5k on a motor that makes less power than one that can be installed for less than 3k...

Myself personally. when I swap in my 351w this winter, alot of the bracket problems will not be major problems. I am going to be installing a tubular K-member, manual steering rack, and eliminating the P/S. so all i will have left IS the alternator.

In the event that the funding will allow me to, i could do a full 351w swap in a 2 week period. Everyone makes it seem like modifying your car is such a big deal, but its really not. Just common sense.

mrbigshot

hell if you start with a complete 351 fuelie the mounts are there. the big killer is the oilpan, the intake, the fuel rails, headers and the distubter.

hell if someone had a fair shape s10 shortbox with a 2.8 i would trade them for my 95 ford 3/4 ton. fuelie roller cam 351w, c6 tranny, and a dana 60 rear.

89GTRed

ALso lots of people just want to mod what they already have. Instead of getting a whole new motor and starting fresh. I think alot of people arent looking for 500-600 hp either, of course everyone would like it but realistically most people wont really go for that much hp. Mine is a DD so i am not looking for a gas guzzling monster. More just a car that will beat most cars on the street and look good as well. Maybe in the future when i have more money, a different DD and am more experienced and have a nice garage where i would actually have the room to do it I would think about it. Of course I am not one who has talked about stroking but i wouldnt mind having a mild stroke job. [sm=drooldude.gif].

I see our point though, if i were looking for a track car or had the provisions listed earlier i wouldnt mind tossing in a stroked 351 in there, and i have often thought about keeping my car until i am ready for it to be a monster weekend driver and doing so.

vristang

Alt bracket stays the same.
Brackets are not the issue for most swaps.

Cost and time are.
It took me several nearly 2 months.
Could I have done it in 2 weeks? Yes.
IF,
-The oil pan had cleared the kmember with mounts I had.
-The upper intake manifold had cleared the stock hood.
And that is just the things I remember.
Things will come up. They always do.
Someone will send you the wrong part, or there will be a mismatch of parts somewhere in your project.
I am not trying to jinx you, but Murphys Law cannot be avoided.

If I didn't have a second car to get to work for that time, then the swap never would have happened.

luckythirteen13

im starting to think a 351 can pass in california. ive seen 347 pass so why couldnt a 351w. run a really mild cam. something between a stock 5.0 cam and a e-cam and it should pass. just put 6 cats on for the test and then an o/r h-pipe after you pass. at teh very least, 4 cats. if my tranny goes, ill be getting a new one made to handle high hp and with a built tranny it will be time for a big motor

VigCS

Yes, this person realizes and and this person has decided against it!

vristang

I am sure I have posted this here, but it seems relevant to this conversation.

http://www.freewebs.com/vristang/fox351wswapfaq.htm




302 to 351W Swap In A Fox Body Mustang

VRISTANG

Note:
This FAQ was written for converting a T-5 5.0 efi Mustang to a T-5 351w efi Mustang. The conversion will be slightly different if starting with a 2.3l or carbureted Mustang OR converting to a carbureted 351w. Converting transmissions is beyond the scope of this document.

Background Info-
The major disadvantage of the 302 is its lack of strength at high power levels. Most will agree that at ~500hp the factory 302 block will try to split in half. For many the solution to this is an aftermarket 302 block.
Another alternative is to swap in a 351w block. There are 2 basic production blocks available; the 69-70 blocks had a deck height of 9.480”, and the 71 up blocks had a deck height of 9.503.” This is compared to the 302 deck height of 8.200”. The 351w is supported by the aftermarket nearly as well as the 302, but can handle much more power than the 302. Some common safe power numbers given for the 351w are usually in the 600-700hp range.

351w Casting Numbers
The casting numbers are on the passenger side near the starter location. You will have to turn the block upside down to see them.

The year will be designated by the first 2 digits of the casting number.
The first digit is the decade and will be a letter. C=1960's, D=1970's, E=1980's, and so on. The second digit will be a number and specifies the year of the decade. Some examples follow:
D1=1971
E9=1989
F4=1994



Getting Into the Nitty-Gritty

The 351w Engine Block -
69-70 - High Nickel content and thicker main webs (These are the only Production Ford 9.480" Deck Height 351w blocks)
71-74 - Reduced Nickel content thinner main webs (71-up had 9.503" Deck Height)
75-91 - Reduced main web thickness
92-On - Lifter Bores were lengthened to accept roller lifters

There were some 351w Mexican blocks as well. These are desirable due to their higher nickel contents. A Mexican block can be identified by the useless looking ***** cast into the block on either side of the timing cover. Mexican blocks were supposedly used on some US vehicles, but they are a very rare find.

Camshaft-
The specs of the cam will depend mostly on what your goals are for the motor. Cam spec selection is way beyond the scope of this FAQ. What you want to watch out for is selecting the correct base circle for the lifter combination and using the stock 302 HO firing order (since you are most likely reusing the stock 302 computer).

69-91 351w blocks -
Option 1) Standard Base Circle Cam / Aftermarket Linked Bar Hydraulic Roller Lifters
Option 2) Small Base Circle Cam / 302 HO Roller Lifters

92 & Later 351w blocks -
The Standard Base Circle Cam can be used with 302 HO Roller Lifters.
A Small Base Circle Cam is not needed in these blocks.
(The 92 and later "roller" blocks will have a F4TE casted into the block near the starter)

If using solid lifters (either flat tappet or roller) then a standard base circle cam can be used on any year 351w block.

If in doubt, ask the company you plan on purchasing the cam from (or better yet a reputable engine builder) what would be appropriate for your application. They will need to know what year the block is and what lifters you plan on running. Additionally it may be helpful to have your rocker ratio available, and what piston you will be using if not stock.
NOTE: Small Base Circle Cams are known to be less than ideal, as they are weaker. Also, there are not as many cam profiles available for the Small Base Circle Cams, so your Off The Shelf Cam selection will be limited. If possible, it is recommended to avoid the Small Base Circle Cams.

Firing Orders-
Early 289 & 302 1-5-4-2-6-3-7-8
302HO & 351w 1-3-7-2-6-5-4-8 (this is all 83-93 Mustangs, and all 5.0 Explorers)

Pushrods-
Again, there are far too many options available to cover here. Check with the cam manufacturer on what length pushrod you will need. Or even better, you can use a pushrod length checker and measure them yourself.

Roller Lifters-
The stock 302 lifters can be swapped over to the 351w (see the cam discussion above) with a little machining and grinding. First the spider will require 2 holes to be drilled in the main valley. These holes will be drilled over the cam bearings, so great care should be taken not to damage the camshaft or bearings. Risk can be minimized by removing the camshaft, and drilling the holes before the cam bearing is installed. Some grinding may need to be done to allow the factory 302 dogbones to sit flush on the 351w block as well. A dremel is adequate to get the job done. Be patient and work slow; it is easier to remove material than put it back. Of course it would be best to do this work before having the block cleaned and prepped for assembly. Ford Hydraulic Roller lifter (for both the 302 and 351w) part number is M-6500-302.
If all of this does not sound appealing to you then maybe some of the aftermarket roller lifters will be a better option. These tend to be fairly expensive however. Look for lifter pairs that have a link bar, connecting each pair of lifters.

Rocker Arms-
This will depend on the heads you select. All of the same rules that apply to selecting rockers for a 302 still apply to the 351w. Options to consider are Pedestal vs. Stud Mount, Roller vs. Non-Roller, and Brand.

Engine Mounts-
Stock 5.0 mounts will bolt up to the 351w. Aftermarket alternatives include solid mounts and polyurethane mounts. Convertible Engine mounts are supposedly reinforced & shorter. Another alternative is lowering engine mounts from HP Motorsports. These are solid and lower the motor ~¾”. Lowering engine mounts are useful for gaining hood clearance, but will also reduce clearance between the oil pan and stock k-member. This presents clearance issues with some aftermarket pans and stock k-members, but should be ok for the FRPP pan. The use of an aftermarket tubular k-member may help improve clearance with aftermarket oil pans.

Heads-
302 heads are basically the same as the 351w heads with the exception of the head bolt diameter. 302 heads have a 7/16” head bolt hole and the 351w has a ½” head bolt. Opening the holes can be done by hand, if done with care. It would be best to send this work to a machine shop however.

Exhaust Headers-
Stock 302 headers will bolt up to the head of a 351w (since the heads are basically the same), but will not mate up to the factory 302 mid-pipe due to the extra width of the 351w. There are many aftermarket suppliers of 351w Fox Body headers including MAC, FRPP, Kooks, Hooker, and Hedman. The Ford shorty headers are p/n M-9430-A58.

Intake Manifold-
Since the lifter valley of the taller 351w is wider than the 302, a new lower intake is required. Aftermarket suppliers of 351w intakes are numerous. Most of these companies offer a 351w lower intake that will bolt up to their 302 upper intakes, which many Mustang owners may already have. Being able to reuse your current upper intake can present a significant $ savings.
Be cautious with intake height if you are trying to clear a stock hood. If the above mentioned drop motor mounts are not used then, another option is to cut down the upper intake. This is easier on the plastic box upper from Comp Cams, as the aluminum intakes will require cutting/welding followed by machining to square up the mating surface.
Shortening the upper intake will cause clearance issues between the TB and valve cover if the upper is trimmed more than ~¾”. Keep in mind that TrickFlow and many other aftermarket head companies have raised the valve cov