351w Crate motor what will I need

[89CobraGT]

I planning of dropping a 351w in my car now I'm thinking it may be more cost effective and reliable the doing up my 302 which has plenty of mods already. I need to know what I will need for this mod. Heres the engine I want to bid on:

http://cgi.ebay.com/ebaymotors/Ford...ryZ33615QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

I'm curoius if I will need a new water pump, timing cover, headers, will my stock transmission handle this?? and what else will I need?? I'm kind of assuming I will need to buy all these parts new. thanx for your help I've set my budget around 7000$ this year for the car im hoping this wil be alot less

 

[304billet]

I would do a crate motor from respectable builders everyone knows, not an E-bay auction. U get what u pay for.

CHP sells 393W longblocks for $4100 with way better parts than the one u have listed. More power more realiability. Another site is panhandleperformance.com and adperformance.com

 

[vristang]

II'm curoius if I will need a new water pump, timing cover, headers, will my stock transmission handle this?? and what else will I need?? I'm kind of assuming I will need to buy all these parts new. thanx for your help

The 302 water pump, timing cover, and trans (it will hold up at least for a while) can be used on the 351w. The headers will need to be 351w in a Fox specific, same as the oil pan.

What mods have you done to the 302? Alot of stuff is the same, making the swap pretty easy.

Here is what I have been posting to the swap questions.

If you have any questions after this, let me know as I will address them as best I can.

302 to 351W Swap In A Fox Body Mustang​

​

Note: This discussion focuses on EFI conversions as this is the most common route taken.

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 / stronger. Another alternative is lowering engine mounts from HP Motorsports. These are solid and lower the motor ¾”. Lowering engine mounts will reduce clearance between the oil pan and k-member. This presents clearance issues with some aftermarket pans and stock k-members, but should be ok for the FRPP pan.

Heads-
302 heads are 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 or sent out to a machine shop.

Exhaust Headers-
Stock 302 headers will bolt up the head of a 351w (since the heads are basically the same), but will not mate up to the 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.

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. Some 351w lowers will bolt up to standard 302 upper intakes, which can help reduce conversion costs. Be cautious with intake height if you are trying to clear a stock hood. Another option is to cut down the upper intake (This is easier on the plastic box upper from Comp Cams. This will cause clearance issues between the TB and valve cover if the upper is trimmed more than ¾”).

Oil Pan-
The 351w is wider so a new oil pan is required. The lowest cost option is probably the FRPP 351w pan for Fox Body applications. Aftermarket companies have standard volume, high volume, drag race , and road race pans available. A pan specific pickup tube and dipstick will also be necessary.

Oil pump-
The 351w oil pump is different from the 302 (mostly external). These are readily available in standard volume, high volume, and high pressure models.

Distributor-
The taller 351w does require a longer distributor. This can found from several stock Ford factory applications, mostly pickup trucks/vans. Some aftermarket suppliers do have electronic/TFI distributors available, such as MSD and Accel. Be sure that the cam drive gear is appropriate for your application. Roller cams require a steel dist. gear.

Engine Management-
Any stock 302 computer will handle a 351w. The EEC-IV will be fine until the combination gets more dramatic with larger injectors, heads, intake, and cam. Aftermarket plug in style chips are not going to offer ideal performance. The best solution is to invest in a chassis dyno tune or an EEC-IV computer tuning system.

Flywheel/Flexplate & Starter
The counter weight of the 5.0 is 50oz. The 351w counterweight is 28oz. You can reuse a 5.0 flywheel if you have it rebalanced at a machine shop. This is probably the easiest and most cost effective alternative. If purchasing new parts just make sure that the flywheel weight and starter tooth count are correct.

Harmonic Damper-
Again this must be matched to the counterweight of the 351w. Another consideration here is getting the crank pulley to line up with the rest of the serpentine belt system. FRPP does have a damper available specifically for this application.

Fuel Injector Rails-
The stock 302 rails will not be wide enough to fit the wider 351w lower intake. If the flex line in the front and rear of the stock rails is removed and replaced with longer sections of high pressure fuel line the stock rails will work just fine.

Fuel Injectors-
Proper injector size will depend on the application.

AC/PS-
This is the only stock 5.0 accessory bracket that requires modification. The stock AC pump and Power Steering pump will bolt up if a ford bracket is used. Without AC (PS only) the FRPP part number is M-8511-A351. For both AC and PS applications the FRPP number is M-8511-B351.

Emissions-
The crossover tube from a 302 can be used if it is cut and a section of high temp hose is used. The 302 air pump will bolt up correctly, and there should be no issues with the air injection system. The EGR should mount up properly, but this will vary with intake manifold selection. Routing of EGR hoses may need to be modified.

Hood-
The easy way to do it is get a taller cowl hood to replace the stock hood. This offers the aggressive look that many are looking for. If desired though, the 351w can clear the stock hood. Clearance will depend on engine mounts and intake manifold selection. If necessary some of the bracing on the underside of the hood can be cut away.

Items Not Affected By The Conversion

Transmission- Just be sure to use the correct input shaft bearing in the crank.
Bellhousing-
Valve Covers
Water Pump
Altenator
Clutch
Timing Cover
Radiator
Timing Chain

 

[bdazzgt]

I am with 304 bullet i would buy from a repeutable company instead of E-bay. They are advertising 468hp and 405lbtq from a pretty much stock bored out windsor with Tw heads and a small 302 cam i call and say u should buy from someone else.

 

[89CobraGT]

Thanks for all your reply's I think I will go with a more reputable company I know some people around here that sell 351w crate motors there just a bit pricey... I just hope my transmission and rear end holds together for the summer lol other then that it should be all good thanks!!!

 

[jruppert]

I actually purchased a CHP 342 and had absolutely nothing but problems with that engine. I will never order and engine from them again. I ended up purchasing a 351w roller from this place that is mentioned and havent had any issues.