351 Windsor Build!!!

[Fox_84]

I am looking to build a 351 Windsor for a Fox Body Mustang. The Stang is Stock as of right now and I am just looking for opinions and personal experience on this same setup and situation. I am looking to do this as reasonablly as possible, but at the same time, I am not looking to cut corners to the point that I regret it later and end up spending more in the long run. This car is a Street Car, but will not be driven daily.
Stroke it or Not? If so how much?
What internals? Pistons, Rods, Cam (want fairly radical to radical), etc.?
What about heads or work to oem heads?
Carb or Fuel Injection? What setup?
I know there is much debate about Automatic or Standard Tranny, quick thoughts?

Dont mean to run this argument into the ground, cuz I know there is much already posted about this same situation, but I am wanting best thoughts about this so I can print and save all replies posted on this topic and use them as I go along the build up.

Not looking to be the baddest at the Strip, but wanna tear um up on the Street. Thanks and look forward to replies.

Looking mostly for guys that have done this and their results and what they would change if they could do it over again. Also, what I will run in to as far as problems and fixes. Also, an idea on costs would be appreciated and where to get parts. Thanks.

 

[Fox_84]

O! and by the way. This is my first thread, I am new to stang net, but not new to the mustang world at all. And the 84 is the birth year of myself, not my model of mustang.

 

[jammer84_03]

cheapest way for big power is stroking what you have....rick91gt has got me thinking about getting a 331 or 347 for a very nice price and i wont have to do a load of conversions to the car to get the 351 to fit. plus i can keep it under the stock hood. the weight of the 351 will put you up 200lbs min. where as a good stroker can net you the same power for the same price (if not less) and weight less as well.

 

[Canadian89GT]

I am in the process of doing the same thing, that is a 351 conversion. As far as added weight, its not that bad. A 302 block weighs 165 lb and and a 351W weighs 195lb, only a 30lb difference. (Dart block) The internals of a 351 are slightly heavier. Its a great option if you have the time and patients. You will need 351 specific header, distributor and manifold. Hooker makes some really nice swap headers and as far as manifold selection goes, you have many. Keep emissions in mind if you car is street driven because depending on how many cubes you go with and your heads, it may be difficult to pass the sniffer.

Good luck..

1989 GT..Dart stroker build in process

 

[69Rcode_Mach1]

I was going to state as well that the weight given on the 351 is inaccurate as well. The difference in weight is 20-30 pounds like CanadianGT stated.

 

[vristang]

Switch to Al heads when you do the conversion and there will be no difference at all

For me there is no debate between carbs and efi. Why would you use an old tech? If your car currently has a carb then it may be an option to stick with that for simplicity, but you would then be giving up some drivability or power or emissions.

I am still using the stock hood on my 408w. Others have done the conversion with the stock hood as well. There are a couple of ways to do it.

The following is something I scribbled down a while back. If you see any errors please let me know, as I have posted this a few times, and will continue to do so until the swap sticky is revived.

351W Swap In A Fox Body Mustang​

VRISTANG​

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

 

[5.0 HOtrain]

My car weighed in at 3240 with me and the aluminum headed 302, with the forged 351 stroker, and heavier flywheel,exhaust, and fuel system the car weighed in at 3308 w/driver.

BTW, to give you some idea, I run a 418 stroker, TFS "R" heads, super victor intake, both out of the box. A hydro roller at 252/262@ .05, 110ls, .576/.576 lift, demon 1000cfm carb, 11.25:1 compression, 1 7/8 long tubes to 3" exhaust. On the engine dyno, and pump gas the motor made 581/539. I went from efi to carbed, sold the efi harness/computer, bought an msd ignition setup. Bought a fuel tank insert and line/fittings, a distributor, and headers. It can be done to clear the stock hood with a 351, I did not go this route and bought a 4" cowl hood. Most of the stuff you buy for a 351 swap is all stuff you will buy to do a 347. You wont see someone build a new stroker and put their old rusty oil pan on it, you wont see crappy 1 5/8 headers on a 400+ hp 347, ect............. JMHO.
Mike.

FWIW, on a shortshifted shakedown pass, the car went [email protected] with the stick and drag radials. With the C4 it has now, should runs 10's on the drag radials with n/p.