Steve Baur
Former Editor, Modified Mustangs & Fords
June 21, 2010
Photos By: Justin Cesler

If you've been following our Street Smart Windsor engine buildup in the last couple of issues, then you'll be happy to know that we finally have the Windsor in our late-model Mustang, we've flogged it on the dyno, and we even took the car to the track just for good measure.

If you're just joining us, what you need to know is that we've set a plan in motion to make a super-streetable engine that makes in the neighborhood of 350-400 hp at the crankshaft. We've specified a stock idle, which meant making concessions on the camshaft specifications, and we kept the Windsor fuel-injected and running off of the stock A9L engine management computer to make this as much of a bolt-in installation as possible.

Our basis for this endeavor is a budget 351W, or more precisely, a 359ci rebuilt short-block from Latemodel Restoration Supply that retails for $999. It comes with cast pistons and connecting rods, but more importantly, it's full of cubic inches-57 more than the stock engine that came out of our subject '89 Mustang GT. Said 5.0L ran very strong with 125,000 miles on the ticker, but in today's world, 225 hp just doesn't get it done, especially when there are four-door grocery-getters packing 40 or more ponies than that.

We looked to fortify our GT with a powerplant of modern horsepower proportions, and so added a set of RHS 200cc Pro Actions cylinder heads, a custom camshaft and rocker arms from Comp Cams, and a stout intake manifold from Trickflow Specialties. Anderson Ford Motorsport opened up the intake tract with one of its Power Pipes, and reading the incoming air charge is an Abaco programmable mass air meter.

At the other end of the combustion process, we made the simple choice of BBK Performance 351W swap shorty-style headers that drop right in and accept any common 5.0L X- or H-pipe. We went with BBK's X-style midpipe with catalytic converters to be somewhat environmentally friendly, but also to keep down the audible presence. Dynomax offered to help out with the sound dynamics as well, and provided us with a set of its brand-new VT series mufflers that feature a pressure-operated door inside the muffler case. This is designed to quell the exhaust note during normal operation, while offering unrestricted, unadulterated flow at wide-open throttle.

While assembling and installing our Windsor, we encountered a number of minor setbacks. Boken-off bolts, incorrect parts, and lack of the proper tool all put us behind the deadline eight ball a number of times. To finish the story in time for this issue-for continuity's sake-we enlisted the help of several good friends, who spent a number of late nights turning wrenches, eating pizza, and of course, breaking balls. We have to thank George Xenos, Rob Baldwin, Chris Crosby, and Brian Bohnsack for helping us get the job done in time. And while we were lucky enough to have a great bunch of friends to call on and bail us out, it just goes to show that no matter how simple a job is, it can be slowed to a snail's slide by the smallest of details. An engine swap is a major job and shouldn't be taken-or planned for-lightly.

A week later, we arrived at Ramsey's Performance In Lutz, Florida, where proprietor Dennis Ramsey offered up his dynamometer services for Muscle Mustangs & Fast Fords. Dennis has been tweaking late-model Mustangs since they were new, and he continues to turn up the heat in Ford's finest today.

With a base '89-'93 Mustang 30-lb/hr mass air meter program loaded in the Abaco DBX97B, we made a hit on the Dynojet and took the Windsor up to 5,500 rpm before clicking it off. On our first pull, we saw 317 rwhp. We were unable to obtain a torque reading using the Dynojet tachometer lead, and despite our best efforts, could not achieve one on subsequent pulls. The Windsor did consistently drop rear-wheel-horsepower figures in the 320s as we fine-tuned the DBX97B using the wide-band air/fuel meter from the dyno and the free tuning software from However we surmised that the numbers might have been slightly skewed due to spikes in the reading.

The Abaco tuning software, like any other software, is slightly imposing at first, but once you have a basic understanding of how it works, you can really take off on your own. We noticed a slight spike in the air/fuel mix that went as high as 14.5:1, and by making changes to the meter's programming, we were able to knock down that area of meter voltage to a consistent 13.0-13.3 across the pull. While our relatively mild camshaft doesn't really show off the DBX's metering capabilities like it would with a big lumpy camshaft, it will provide accurate air measurements for our profile and anything else we may throw at it in the future.

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