5.0 to 5.8 swap? - Page 2 - MustangForums.com

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5.0 to 5.8 swap?

Old 03-06-2007, 08:59 PM
2 kwik
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Default RE: 5.0 to 5.8 swap?

the cam in that engine is[:'(]
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Old 03-06-2007, 09:01 PM
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Default RE: 5.0 to 5.8 swap?

ORIGINAL: 2 kwik

the cam in that engine is[:'(]
all too true. it makes nice low RPM torque though... for a stock cam that is
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Old 03-06-2007, 10:55 PM
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Default RE: 5.0 to 5.8 swap?

IMO, You will need to get some 'low-rise' engine mounts OR get a new hood if yours is stock due to the fact the 351W is taller and may not give ya ANY clearance.
You'll probably need new headers too. Hooker has them.
Also, fully dressed all iron 351W is about 75-90 pounds heavier than 5.0.
Do you really want that much more wieght on the front of a car that already has 58% of it's wieght on the front wheels. (If it's a 'stocker')...........
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Old 03-07-2007, 01:29 AM
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Default RE: 5.0 to 5.8 swap?

90 lbs? Are you high? Its the same motor with like an inch taller deck you dofus.
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Old 03-07-2007, 03:45 AM
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Default RE: 5.0 to 5.8 swap?

I'm tired so I am just going to post this and go to sleep...

Revised - 2/26/07[/b]

302 to 351W Swap in a Fox Body Mustang


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.[/i][/b]

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, which can be expensive.
Another alternative is to swap in a 351w block. 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. 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”.

351w Casting Numbers
The casting numbers are on the passenger side near the starter location. You will have to turn the block upside down, or use a mirror 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 andspecifies the year of the decade. Some examples follow:

For more info on how to identify various Ford engine blocks check out the following link…

Getting Into the Nitty-Gritty

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

There were some 351w Mexican blocks as well. The early versions of which are desirable due to their beefier castings and higher nickel contents. A Mexican block can be identified by the useless looking ***** cast into the block on either side of the timing cover, and an “Hencho en Mexico” cast into the lifter valley. Mexican blocks were supposedly used on some US vehicles, but they are a fairly rare find.

Camshaft and Lifters-
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 302computer).

69-91 351w blocks -
Roller Lifter Option 1) Standard Base Circle Cam / Aftermarket Linked Bar Hydraulic Roller Lifters
Roller Lifter 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 Camsare known to be less than ideal, as they are weaker. There are not as many cam profiles available fortheSmall Base Circle Cams, so yourOffthe Shelf Cam selection will be severely limited. If possible, it is recommended to avoid the Small Base Circle Cams.

Firing Orders-
Early 289 & 3021-5-4-2-6-3-7-8
302HO &351w 1-3-7-2-6-5-4-8 (this is all 83-93 Mustangs, and all 5.0 Explorers)

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/grinding and a reduced base circle cam.
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 bearings are installed. Some grindingmay 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 rumored to be stronger & shorter. Another alternative is a set of lowering engine mounts from either Year One, Moroso, or HP Motorsports (HPM). 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.
Un-Confirmed – [/i][/b]
From 87-90 the convertible Mustang had the “captured” mount design, while the Hardtops had the standard design. The captured style mounts are said to be ½” to 1” lower, and to be stronger.[/i]
In 90 and later Mustangs, ALL were equipped with the captured design.[/i]
Aftermarket Prothane mounts are said to mimic the design of the early Hardtops. While the Energy mounts are said to mimic the convertible “captured” mounts. So, Energy Engine Mounts should be the same height as the 87-90 convertible “captured” motor mounts
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