Mustang Restomod Guide: Drivetrain
Modernize Your Drivetrain With Crate Engines, Strokers, And Overdrive Transmissions
Last month, we covered the exterior modifications that make Mustangs look so great. This month, we're talking about power and getting it to the pavement. Put them together, stir in some suspension and interior updates-which we'll cover in the next couple of issues-and you have the makings for a top-notch Mustang restomod.
During the past 10 years, the restomod movement has made its mark on the vintage Mustang hobby and industry. No longer are Mustang owners ostracized at shows for ditching factory-original equipment for larger wheels and tires, late-model stroker engines, and Shelby scoops. While we agree that some Mustangs should be preserved in their original state-Shelbys, Bosses, Cobra Jets, and other special models-the huge majority of the more than 3 million '65-'73 Mustangs that Ford produced were basic coupes, fastbacks, and convertibles. There's nothing wrong with taking those cars and making them better. After all, that's what we did with them when they were new in the '60s.
Of course, back then we didn't have roller-cam engines and overdrive transmissions. With today's modern drivetrain technology, older Mustangs can be updated for more power and better efficiency with improved fuel mileage in these days of $2 or more for a gallon of gasoline.
It's The Boss
For many years, Ford Racing has offered a number of crate engines based on the ever-popular 5.0L. But at last year's SEMA Show, the company unveiled its small-block crate engine of the future. Called the Boss 302 in tribute to the legendary small-block from '69-'70, the engine is based on a new block with four-bolt mains. The line was conceived out of the need for engines built from a stronger block than regular-production 302s.
Built from the new Boss 302 block, Boss crate engines feature performance and packaging that accommodate displacements from 302 to 363 ci. Entry-level engines are rated at 340 and 345 hp with Ford Racing's GT-40X Turbo Swirl aluminum heads, which retain stock exhaust locations. Higher performance versions include the company's Z-head-equipped 302 and 347 engines rated between 360 and 450 hp, depending on configuration. The Boss engine series is capped by a 500hp, 331ci version with ported Z-heads.
The suggested retail price for the Boss crate engine ranges from $4,650 to $10,000 for the 500hp Boss 331. The engines come with a 12-month/12,000-mile limited warranty.
Few things look better on top of a well-dressed small-block than Tri-Power induction. While developing a two-barrel carburetor for the oval-track racing market, the engineers at Barry Grant's Demon Carburetion realized that stacking three of the carbs together on a single-induction package would recreate the muscular looks and nostalgic appeal of Ford's original Tri-Power setup. So three of the Barry Grant companies-Demon Carburetion, Triple-D Induction, and Rush Performance Filters-banded together to collaborate on a new Six-Shooter induction system for 289/302 small-block Ford engines.
Featuring a trio of 250-cfm carburetors, the Six-Shooter mounts the carbs backward to avoid distributor-clearance issues, similar to Ford's Tri-Power. The center carb does all the work during normal driving, including cold starts, with its electric choke. The outer carbs get their orders to open from a progressive throttle linkage. The Six-Shooter also comes with a polished, oval air cleaner from Rush Performance Filters.
For the past 10 years or so, the PerTronix Ignitor and Ignitor II electronic ignition modules have been a popular replacement for the archaic points and condenser in vintage distributors. Now PerTronix offers the electronic upgrade in a new billet distributor.
The complete, ready-to-drop-in distributor is loaded with features, including the Ignitor II module already installed in the CNC-machined aluminum housing. The bottom half contains a self-lubricating, oil-impregnated, copper-powder bushing to reduce friction and high-rpm vibration. Available from Mustangs Plus, the PerTronix billet distributor fits 221, 260, 289, and 302 small-blocks. Cleveland and FE versions are expected in the near future.
We Be Stroking
Replacing a 289 or 302 with a stroker small-block is an outstanding way to gain performance in an early Mustang without detracting from its vintage appearance. With a 347 version of the late-model 5.0L, you get 58 more cubic inches thanks to a 0.040-inch overbore and longer stroke crankshaft. The external dimensions are the same as a 289 or 302. Other displacements are available, and most come with the newer-style roller camshafts. The newer block bolts right up to bellhousings for either a late-model AOD or five-speed, or a vintage C4 automatic or four-speed. You'll have to locate an adaptor for a vintage-style clutch linkage because late-model blocks don't have the threaded boss for the linkage stud.
The 5.0L is based on the same engine family as vintage 289s and 302s, so valve covers, intake manifolds, and accessories are typically easy bolt-ons.
Small-block Ford stroker engines are available, either as short-block or long-block crate engines, from a number of sources, including Ford Racing, Smeding Performance, Coast High Performance, and Roush Performance.
Stainless Works has introduced a larger version of the popular Try-Y headers for small-block Ford engines in '65-'73 Mustangs. Featuring 151/48-inch primary tubes for improved flow, the headers are manufactured from 304 stainless with 11/44-inch thick, CNC laser-cut flanges. The tubes transition into 2-inch intermediate tubes before dumping into 3-inch collectors with either a three-bolt flange or a patent-pending slip-fit design, allowing the exhaust system to slip over the collector for securing with a T-bolt clamp. Dyno tested, the Stainless Works 151/48-inch Tri-Ys made 36 more horsepower at the rear wheels compared to traditional 111/42-inch Try-Y headers.
It's the big daddy of Mustang bolt-ons. Originally a rare option for '66-'67 Shelby GT350s, the Paxton supercharger is back for carbureted, vintage Mustangs with a modern Paxton Novi 1200 supercharger. Designed to fit '65-'66 Mustangs, the Novi blower generates 6 to 7 pounds of boost and works with stock four-barrel engines or--better yet--modified engines. With the carburetor housing, brackets, and all other components needed to install the system, it's fairly complicated for a bolt-on. And it's not cheap. But once you feel the boost, it's worth it.
For more than a decade, installing an AOD transmission into a vintage Mustang has been a popular upgrade compared to original C4, C6, and FMX three-speeds. With a modern AOD, you get reduced engine rpms at highway speeds, better fuel mileage, less engine wear, quieter cruising, and improved off-the-line acceleration when used with lower (numerically higher) rearend gears. These days, it's practically a bolt-in swap because much of the research has been done.
Used AODs are available from many sources, but if you're going through the trouble of making the swap, it's best to choose one that has been rebuilt to performance specifications by companies such as Performance Automatic, Lentech Automatic, and B&M Automotive.
In addition to the actual transmission, you'll also need an aftermarket crossmember, a flexplate, a shift linkage to connect the AOD to your vintage-style shifter, a kick-down linkage, and a throttle-valve cable to adapt to the carburetor. The cable acts as the equivalent of the older vacuum modulator. In most cases, the driveshaft will need to be shortened by about 1 inch.
Several companies, including Performance Automatic and Ron Morris Performance, offer adaptor kits for installing an AOD in early Mustangs.
For good looks and the extra benefit of reducing power-robbing drag from engine accessories, Redd Manufacturing offers the Concept One pulley system for Fords, including Windsor small-blocks, FEs, and 429s. CNC-milled from 6061 billet aluminum and available in machined or polished finishes, the pulley systems are supplied with the necessary components, including Goodyear Gatorback belts and chrome-plated fasteners. All the Concept One kits feature overdrive technology for increased water pump flow and electrical charging at idle and slow speeds.
Modular To The Max
While most Mustang restomodders choose stroker small-blocks for power, there are some who take restomodding to the max by taking full advantage of today's modern drivetrain technology. David Stribling from DVS Restorations built his "Mustang in Black" '68 Mustang fastback with a complete drivetrain from a '99 Mustang Cobra-a Four-Valve 4.6L engine, a T45 five-speed, and an 8.8-inch rearend in the Cobra's IRS rear suspension. Of course, much fabrication was needed. In the end, David's Mustang project proves that if you want modern technology bad enough, you can adapt it to a vintage Mustang.
Any vintage Mustang is an ideal candidate for a five-speed swap. Many opt for the T5 five-speed, although newer and improved versions such as the Tremec TKO are also a popular choice. As with the AOD automatic, you get the benefits of an overdriven Fifth gear for improved fuel mileage, quieter cruising, and quicker acceleration, especially when used in conjunction with a lower rearend ratio.
In addition to the five-speed transmission, you'll need a number of other components for the conversion in an original four-speed car, including an adaptor plate for the bellhousing, crossmember, shifter, transmission mount, and yoke. Companies like Ron Morris Performance and California Pony Cars offer the various components, while Keisler Engineering has put together a one-stop shopping option with its Perfect Fit packages, which include everything from the transmission and crossmember to installation of the hardware.
If you're swapping from an automatic to a five-speed, you'll need a few additional parts, including the bellhousing, clutch, clutch-cable kit, and a manual-transmission pedal setup that includes the clutch pedal.
Pump It Up
A great addition to any Ford small-block or 429 engine is Edelbrock's aluminum water pump. Offering better flow, optimum pressure, and equal distribution to both sides of the block, the company's all-new water pump assures proper cooling when used in conjunction with a performance radiator and fan.
DVS Restorations has developed a universal crossmember designed to adapt most popular Ford transmissions, including five-speeds and AODs, to the vintage Mustang's original rubber insulator. Adjustable a full 6 inches in all directions for unique engine/transmission/ front-suspension combinations, the DVS crossmember also adjusts to variances and twisting in the original chassis. The special Nordlock locking system ensures the crossmember configuration holds tight. It can also be welded if desired.
Currie Enterprises continues to make it easier to build a durable rearend without having to scrounge the junkyards for old axles. As part of Currie's 9-Plus line of upgrades, the 9-Plus Sportsman gearcase casting is basically a new 9-inch housing made from nodular cast-iron and complete with caps, cap retaining bolts, billet spanner nuts, and spanner-nut retainers. With diminishing availability of original 9-inch parts, Currie set out to redesign and build new 9-inch rearends, resulting in the 9-Plus line of axle components, including complete 9-inch housings.
Light In The Head
We've come a long way in cylinder-head design since the '60s. With the proliferation of 5.0L performance in the late-'80s, performance aftermarket companies such as Ford Racing and Edelbrock invested the R&D needed to create better flowing heads for the Windsor small-block. The result is aluminum heads with larger valves and superior port designs to maximize flow for optimum performance. Weight savings compared to factory cast-iron heads are another benefit.
Edelbrock's Performer heads are proven performers when bolted to '65-'95 289, 302, 351W, and 5.0L engines. With large, contoured intake ports, the heads are capable of at least 300 hp when matched with other components from Edelbrock's Total Power Package. Two versions of the Performer head are available. For relatively stock engines, the version with 1.90 intake valves eliminates any concern about piston-to-valve cAlearances. For engines with notched pistons, a second version with 2.02-inch intake valves adds additional flow capabilities. Both versions of the Edelbrock Performer heads have 1.60-inch exhaust valves and 60cc combustion chambers.
Aluminated For 8s
For many street Mustangs, an 8-inch rearend is ideal. It's lightweight, consumes less power, and delivers relia-bility. Now Currie Enterprises offers a solution to the 8-inch axle's weakness: the thin pinion pilot support. Currie's Alumin8 gearcase puts more meat around the pinion pilot to eliminate that weakness. Precision made from 206T6 aluminum, the Alumin8 differential housing is ideal for high-power street applications.
The '65-'66 Mustang wasn't designed for big-block engines, but that has never stopped restomodders. When Merv Rego at Classic Creations of Central Florida built a '66 Mustang sedan delivery, he wanted an eye-popper underhood. By eliminating the shock towers with a Heidt's Hot Rod Shop Mustang II-style front suspension, Merv created a cavernous engine compartment for the installation of a 514ci monster from Jon Barrett Hot Rod Engines. Based on Ford's 385-series 429/460, the stroker 514 looks impressive while delivering plenty of streetable torque. Sanderson street-rod headers work perfectly with the Heidt's front suspension, while a Performance Automatic Super Comp AOD transmission provides exceptional durability behind the 514, while also lowering cruise rpms.
With the proliferation of five-speed swaps into vintage Mustangs, a number of companies now offer crossmembers to join modern transmissions to older chassis. Pictured from left to right are versions from Ron Morris Performance, JBA Performance (perfect for a Mustang with JBA's exhaust system), and California Pony Cars. Which crossmember you use for your application depends on fit and clearance issues.
It doesn't always have to be wild and crazy-at least, not on the outside. Mark Binding wanted the pleasure of a restomod with the looks of a concours restoration. For his '65 convertible, Mark ordered a Ford Racing M-6007-XB3 long-block and dressed it up to look similar to a stock 289, right down to the black paint, era-correct hose clamps, and yellow-top coil. To fit roller rockers underneath the vintage Cobra valve covers, he employed valve-cover spacers-painted black-to complete the disguise. Behind the covert engine is a T5 five-speed, which is also disguised with an original shift linkage and a four-speed ball knob.
For excellent ground clearance as well as clearing the steering and suspension components, Patriot Exhaust, a division of PerTronix, offers Clippster-style headers for 260-302 small-block engines in '65-'73 Mustangs. Designed to fit best with '6611/42-'70 motor mounts, the Clippster headers are shorter than full-length versions with collectors that exit toward the rear of the engine compartment, providing additional clearance around other components. Large 151/48-inch primaries and 3-inch collectors improve exhaust-gas velocity to increase horse-power and torque. The headers won't fit manual transmissions with a mechanical clutch linkage, but they will fit '85 '95 bellhousings using cable clutch kits.