Muscle Mustangs & Fast Fords
Ford Mustang 351 Windsor Engine Replacement Part 2
We Show You What It Takes To Drop A 351 Windsor Engine Into Your Fox-Body. It's Not That Difficult. Trust Us.
What stays and What goes?
If you're pulling parts from your 5.0L, here's what you can reuse: the timing cover can be swapped, and since the water pump bolts directly to it, you can just leave that on there when you pull it off the motor. Many people feel that upgrading the water pump is a good idea in any high-performance application, especially with a Windsor engine, but for our build, we think the stocker will work just fine. The timing pointer, alternator, and bracket all make the change without issue. The other side of the engine is where you run into problems.
With driveability being a driving factor in all of this, naturally we will want to keep our air conditioning and power steering intact. To accomplish this, the easiest thing to do is call your nearest Ford Racing Performance Parts dealer and order part number M-8511-B351, which will get you a pair of brackets that allow you to bolt your A/C compressor and power-steering pump to the taller Windsor block. If you're skipping the A/C and just want power steering, order part number M-8511-A351; If you're sticking a 351 in an SN-95, skip both of these and bolt the components directly on.
We ordered our brackets from Holcomb Motorsports in Lumberton, North Carolina. Holcomb has long been known in the Mustang hobby as an engine swap specialist and offers everything you need to make it happen. You'll also need a different serpentine belt; we'll share our part number once we have everything mocked up. Note that belt length varies depending on pulley choice.
The harmonic balancer and flywheel can be shelved, as you'll need pieces that feature a 28-ounce balance weight, as opposed to the 5.0L's 50-ounce heft. We had one of FRPP's M-6316-C351 SFI balancers left over from a previous tech article and opted to use that, though for a budget build like this, a stock 351 balancer would work just fine. You'll have to check your crank pulley alignment, as you may need a spacer to keep everything on the same plane. FRPP has those as well. Whatever balancer you use, remember that your 5.0L crank pulley has four bolt holes. You can reuse it provided you get a balancer with four, rather than three holes.
Most 5.0L cylinder heads will fit on a 351 Windsor, but you'll have to make sure the bolt holes are drilled out, as the 351 uses half-inch bolts/studs whereas the 5.0L uses 7/16-inch pieces. Yes, Ford put the little GT-40 heads on the 351 in the Cobra R and SVT Lightning, but there are so many better options out there now that it just doesn't make sense to do that unless budget weighs far more heavily than the ultimate performance goal. Remember you're dealing with a 351ci (359 in our case) engine that requires a lot more air than your stock or near-stock 302 engine, so most of you are going to want heads with an intake runner no less than 180-200 cc in size.
Since all of these cylinder heads fit 302s as well, the lower intake bolts are all the same and can be reused. The 5.0L headers can be reused if you have a custom midpipe fabricated, but companies like BBK Performance make it easy for you by offering shorty swap headers that bolt right up to your existing X- or H-pipe. Yes, you can get a long-tube header and midpipe assembly as well, but we went with the shorties for their ease of installation, maintenance, and the relatively mild power potential of our combination. Beyond that, your 5.0L bellhousing and clutch will bolt right up, but you'll need the aforementioned 28-ounce flywheel to connect the dots. These are readily available most anywhere, but we went to Summit Racing Equipment in Tallmadge, Ohio, for a Ram 157-tooth, billet-steel flywheel (PN RAM-1527).
Summit Racing also provided us with a number of other items that you'll see throughout the build. With three warehouses scattered across our great country, you're just about guaranteed to get your high-performance goods within a day or two of ordering. Since one of the warehouses is based in Atlanta, we got one-day turnaround service to our Tampa, Florida, office.