Imagine the convenience of an off-the-shelf crate engine displacing 427ci that you can assemble and install in your Mustang over a weekend. On the outside, it looks like a 351W small-block. Inside, it displaces big-block cubes ready to make axle-twisting big-block power.
We caught up with Scott Drake Enterprises’ Jerry Choate and his wife, Carlyn, as they were building a ’65 Mustang fastback in their Las Vegas shop. The power objective was a civil yet aggressive 351W-based stroker, something that would come on strong at wide-open throttle, yet be passive enough for a road trip with a five-speed manual and compromise cogs in back. Jerry knew from experience that you can overbuild to the point where the Mustang becomes a chore to drive.
Jerry chose Ford Racing’s new BOSS short-block, M-6009-427F, displacing 427ci for a small-block that thinks it’s a big-block. Ford Racing begins with the M-6010-BOSS35195 block with four-bolt mains and 9.500-inch deck height, then fills the bulletproof short-block with a Scat 4340 4.000-inch steel crankshaft with 4340 H-Beam 6.200-inch connecting rods and Mahle 4.125-inch forged pistons with valve reliefs for Z304, N351, GT-40 or other inline valve Windsor cylinder heads. It’s compatible with hydraulic roller tappets and comes completely assembled for under $5,000.
Although the short-block arrives as a ready-to-complete assembly, there are items you need to check when you get it on an engine stand, including crankshaft endplay, connecting rod side clearances, rear main seal (should have assembly lube on lip), piston deck height, cam bearing condition, block plugs (are they tight?) and cooling passages and oil galleries to make sure they are clear. These checks should be performed on any engine you receive, whether it’s a crate engine or a custom build from a local shop. It is easier to check these things now then have to pull the engine later on because you missed something.
The beauty of the M-6009-427F short-block is that you can go in any direction with heads, induction, and cam. Because this is a high-performance short-block with 4.125-inch forged pistons, 4.000-inch stroke, H-beam rods, and steel crank, it is for high-rev activity, meaning you can commute Monday through Friday and go racing Saturday night depending on what you do with cam and induction.
You have a choice when it comes to cylinder heads for the BOSS M-6010-BOSS35195 block. We decided to go with one of the two Ford Racing street/race heads for the BOSS block—M-6049-X306 with 64cc chambers. There is also the M-6049-X307 casting with 58cc chambers. Choice depends on how much compression you want. Ford Racing’s Jesse Kershaw recommended the 64cc chamber to keep compression safe for pump gas. These are basically GT-40 Turbo Swirl heads with nice revisions like beehive valve springs, 1.94/1.54-inch valves, and tight wedge chambers with plenty of quench. Ford Racing tells us these are easily 65 bolt-on horsepower. Of course, your results will vary depending upon cam selection and building technique.
Choate delivered the X306 heads to Steve Baker at Baker Cylinder Heads for minor prep work to help improve airflow and get rocker arm geometry where we wanted it. For camshaft, Choate decided to go with an off-the-shelf Extreme Energy roller hydraulic camshaft (part number 35-427-8) from Comp Cams with link bar hydraulic roller tappets and one-piece, thick wall pushrods. On top, he mounted Harland Sharp 1.6:1 roller rocker arms on ARP 7⁄16-inch studs.
With a Holley 750-cfm four-barrel carburetor and Edelbrock Performance intake, Choate believes this 427W will make in excess of 500 horsepower and roughly 550 lb-ft of torque.
1. The Ford Racing M-6009-427F...
1. The Ford Racing M-6009-427F short-block is a race-ready foundation with Mahle forged pistons, 4340 H-beam rods, 4340 steel crank, and the new BOSS M-6010-BOSS35195 9.5-inch deck height block. It’s the deck and larger 4.125-inch bores that enable Ford to huff 427ci into this block.
2. Down under is 4340 steel...
2. Down under is 4340 steel crank with 4340 steel H-beam rods protected with four-bolt main caps.
3. The Mahle 4.125-inch pistons...
3. The Mahle 4.125-inch pistons are dished to keep compression safe. The huge valve reliefs that should clear 2.02/1.60-inch valves if you wanted to go that large.
4. Although the M-6009-427F...
4. Although the M-6009-427F is professionally built and dynamically balanced, always check details as you would any engine—connecting rod side clearances, piston deck height, cam bearings, oil and cooling passages, rotating mass to block clearances, and block plugs.
5. The M-6009-427F BOSS block...
5. The M-6009-427F BOSS block uses special head gaskets (M-6051-CP331 or M-6051-S331) available only from Ford Racing or Summit Racing Equipment. And remember, they are right and left bank specific. They do not interchange. Look for the “1031L” or “1031R” and “UP” on each gasket. These gaskets are not shaped like traditional small-block Ford head gaskets.
5a. Look for the “1031L” or...
5a. Look for the “1031L” or “1031R” and “UP” on each gasket. These gaskets are not shaped like traditional small-block Ford head gaskets.
6. Ford Racing’s X-Head is...
6. Ford Racing’s X-Head is a refined version of the popular GT-40 head and is available in two versions, the M-6049-X306 with 64cc chambers and the M-6049-X307 with smaller 58cc chambers. These heads are the same except for chamber size. Jesse Kershaw of Ford Racing recommended the X306 head with 64cc chambers to keep compression in check for today’s pump gas.
7. A nice refinement is the...
7. A nice refinement is the beehive valve springs, which can handle more lift and behave nicely at high rpm. These springs are designed for our Extreme Energy cam and can withstand up to .600-inch lift.
8. Heads are torqued in proper...
8. Heads are torqued in proper sequence from inside out to 85 ft/lbs in one-third values. With a wet deck (bolt holes into water jackets), use a commercial grade Teflon sealer on the bolt threads.
9. Comp Cams tie-bar style...
9. Comp Cams tie-bar style hydraulic lifters (#838-16) get liberal doses of engine assembly lube and are installed with the link toward the valley, not the block.
10. Comp Cams offers this...
10. Comp Cams offers this convenient pushrod checker (#7702) for mock-up work to determine proper valvetrain geometry. You want the roller rocker tip smack in the middle of the valve stem tip at maximum valve lift. This is determined by pushrod length.
11. The Harland Sharp roller...
11. The Harland Sharp roller rockers from Summit Racing Equipment offer a 1.6:1 ratio and are secured by poly-locks. More aggressive lift can be had with 1.7:1 rocker ratio. However, valve to piston clearances must be checked along with the potential for valve spring coil bind.
12. Intake manifold gasket...
12. Intake manifold gasket preparation is crucial to proper operation and durability. The early 351W dogleg cooling passages need to be trimmed for unobstructed flow.
13. Manifold heat passages...
13. Manifold heat passages should be blocked, which may adversely affect cold start operation but will pay dividends when things get hot. The cooler your intake manifold, the better.
14. Edelbrock's Performer...
14. Edelbrock's Performer RPM dual-plane manifold is the perfect street/strip induction system because the long, raised roof runners deliver excellent low to mid-range torque and come on strong at high rpm. Use Permatex’s The Right Stuff at the end rails and lightly around cooling passages. If you want even more torque, opt for a �- to 1-inch carb spacer (hood clearance permitting).
15. Thermactor port plugs...
15. Thermactor port plugs (#TE-3818 from Parts Dinosaur must be installed unless you are running a smog pump (yeah, right…). External thread is 5⁄8-inch at 11 threads per inch. Internal thread is 7⁄16-inch at 14 threads per inch.
16. We’re running a Melling...
16. We’re running a Melling high volume oil pump propelled by an ARP pump shaft. Always disassemble your new pump for a blueprint check. Check rotor end clearances and pressure relief valve for freedom of movement and spring pressure. Take note of rotor indexing before disassembly. When complete, fill the cavity with engine assembly lube or SAE 30-weight engine oil. During installation, check clearances between the pump and the crank counterweights. You need at least .060-inch. Never remove metal from the crank.
17. Why mess with a four-piece...
17. Why mess with a four-piece oil pan gasket when you can get by with a one-piece? Milodon makes this cool one-piece gasket with reinforcements.
18. Choate opted for a road-race...
18. Choate opted for a road-race Milodon pan with baffling designed to keep oil around the pick-up in hard cornering. He also used ARP pan studs, which makes installation even easier.
19. Edelbrock's #1725 Performer...
19. Edelbrock's #1725 Performer RPM fuel pump has a 3⁄8-inch NPT inlet and makes 10 psi at 110 gph. It’s a good idea to run a pressure regulator to keep pressure constant.
20. We’'ve opted for Edelbrock’s...
20. We’'ve opted for Edelbrock’s #8843 left-hand-inlet high-flow water pump, which is available in four finishes—satin (shown), polished, black, and EnduraShine.
21. The harmonic balancer...
21. The harmonic balancer is installed next with liberal amounts of assembly lube on the balancer and crank seal. This is a Ford Racing SFI-approved balancer engineered for high-rpm use. One trick learned from Marvin McAfee of MCE Engines is to put the balancer in boiling water, which allows expansion so it will slide right on the crank.
22. The Edelbrock Performer...
22. The Edelbrock Performer RPM manifold calls for a Boss 302 heater elbow, which rises high enough to clear the runners. Note the crimped “C” design, which restricts flow and pressure to the heater core.
23. Holley provided a 0-4779C...
23. Holley provided a 0-4779C 750-cfm carburetor, a Double Pumper 4150 with mechanical secondaries for quicker throttle response. It has a manual choke for better control during cold start. This is a more traditional Holley in terms of appearance.
24. We’re lighting the mixture...
24. We’re lighting the mixture with an MSD #8578 Pro Billet distributor fitted with a #85834 steel gear for compatibility with the Comp Cams roller hydraulic cam. You must run a brass or steel gear with a roller cam. Ideally, you will opt for the steel gear for durability.
25. It’s always a good idea...
25. It’s always a good idea to compliment your MSD distributor with a support system engineered by the same company. You can hide the 6AL box behind the firewall, which protects it from heat and road debris. MSD ignition wires are custom cut so you can measure and fit them to your application. Remember, your factory ignition lead is a resistor wire and should not be used to power your MSD system. You want power direct from the ignition switch or via a ballast resistor if provided by MSD.
26. Neatness counts, especially...
26. Neatness counts, especially with ignition wires. Made-4-You Products makes these really slick ignition wire holders, available from Summit Racing Equipment, which are easy to install and service. Ignition wire routing is important to prevent crossfire and rough operation.
27. When we contacted Jim Hairston at JBA Headers, he turned us onto the #1653S mid-length header for 351W in a ’65-’66 Mustang, which is a tight fit but perfect for this header combo. The #1653S header is made from ceramic-coated stainless steel with a ball and socket collector design, which means no collector gaskets to fail. This is a nice compromise between a shorty and a long-tube header.