notchback50

I read a lot of the other threads on here about this but i was just want to hear it for myself. what is the best way to go? i want to put a 351 in my car, should i use a fuel injected motor or caburated? and what are the pros and cons? 4 bolt main?

50lxnotch

definately fuel injected cause 90% of the parts from a 5.0 is compatible with a 5.8. pros: more displacement, stronger block cons:none

AdderMk2

im dropping a 351 into my 94 cobra

why???

because it fits

vristang

Fuel injected is the way I would go. Actually, it IS the way I went.

If you are looking for a street driven engine then efi is highly recommended.
If it is track only, or you prefer to go carb, then by all means...


None of the factory 351w blocks came with a 4 bolt main.
I think the confusion comes from the Boss engines of old?

If you are starting with an efi car, then all the efi parts you need for the 351w conversion are already there. EFI wise there is little difference between the 302 and 351w.

If wanted I can post my 351w swap info again...


jason

notchback50

theres no trucks with a 351 4-bolt main? and i would like some more knowledge on ur swap?

vristang

Not using a STOCK block.
I am pretty sure the cleveland 351's had 4 bolts though.

I have some good block selection stuff below.

Hope it formats ok this time.
http://www.freewebs.com/vristang/fox351wswapfaq.htm

[size=2]302 to 351W Swap In A Fox Body Mustang


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 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 69-70 blocks also had thicker main webs and higher nickel content, making them significantly stronger. From 70 to 74 the 351w maintained some of the higher nickel content, but lost some of the material in the main webs. Another small reduction in the main web thickness occurred in 75, along with another reduction in Nickel content (supposedly). In 1992 the lifter bores were lengthened (made taller) in order to accomodate standard roller lifters and standard base circle cams. From 1994 on, all 351w blocks were equipped with roller cams/lifters.

Note: The nickel content statements above have not been verified





Getting Into the Nitty Gritty



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 assimbly. 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 cover flange up to .300� which will limit how much you can trim from the upper intake. Of course the use of tall aftermarket valve covers will be somewhat restricted as well. If you do plan on cutting the upper intake, be sure to do a full mock up with all parts that will be installed later. The part numbers for the Ford 351w Cobra manifold are as follows; Upper M-9424-D50 / Lower M-9461-D58.


Oil Pan-
The

notchback50

thanx for the great article. what if i was to jus throw a whole 351 motor in not jus the block and keep all the 351 stuff on it instead of puttin the 5.0 stuff on it?

vristang

You could run the 351w long block, but it would be less than ideal. The cam and heads are pretty poor, especially if you want to rev it.

I would suggest at least pulling the cam for a good street cam.

notchback50

what would i get for a good cam so that it could run with the 5.0 computor? i would prolly do a H/C/I swap anyway

50lxnotch

i would go with a ford racing cam or a tfs stage 1 cam if its gonna be a DD.