Bowler Tru-Street Ford 4R70W Performance Transmission and Converter Only for SBF Engines (Up to 420 lb-ft of Torque)

High-performance Bowler Tru-Street 4R70W transmission and converter for Small Block Ford engines making up to 420 lb-ft. Built with premium components, recalibrated valve body, stronger internals, upgraded lubrication, and fully dyno-tested. No controller or accessories included.

If you're running a Small Block Ford and you want a transmission that actually handles real power, survives real street miles, and delivers real performance, this is the 4R70W you buy. No gimmicks. No repackaged stock build. No “mild street upgrade.” This is Bowler’s Tru-Street Series, engineered for people who want to DRIVE their cars—not babysit them.

Most “performance” 4R70W transmissions out there are just freshened stock units with a fancy label.
This isn’t that.
This is a Bowler build—purpose-built, dyno-tested, and constructed the way a performance transmission SHOULD be built.

If you want reliability, repeatability, shift quality, and a transmission that can take abuse without complaint… this is your transmission.

What You’re Actually Buying

A professionally engineered 4R70W built for Small Block Ford engines up to 420 lb-ft of torque, designed to outlast and outperform anything in its price range.

Includes:

• Bowler 4R70W Performance Transmission
• 1800–2000 rpm Stall Single Disc Lock-Up Converter
• Electronic speed sensor (mechanical available—ask us)
• Complete Bowler inspection + dyno test
• 24-month limited/conditional warranty
• No core required

Does NOT include:
Controller, fill tube, cooler, yoke, driveshaft, flexplate, crossmember, fluid, or accessories.
(We recommend our Tru-Street Installation Package.)

Why This Transmission Exists

Because SBF owners deserve a transmission that actually supports modern builds.
You’re not building a car for Sunday parking-lot cruises—you want something you can put real miles on while enjoying crisp shifts and dependable performance.

This unit is built to do EXACTLY that.

Inside the Build (This Is What Makes It Better)

• All-new clutches, steels, seals & gaskets
• New OEM solenoids (EPC, TCC, PWM, shift solenoids & MLP sensor)
• Pro Series wide OD band for increased surface area
• Updated molded 2–3 accumulator piston
• Increased line pressure for firmer, more durable clutch engagement
• Recalibrated valve body for improved shift control
• Updated bypass valve + pressure regulator valve
• Stainless steel sun shell upgrade
• New Torrington bearings
• Improved lubrication circuit for better thermal stability
• Updated mechanical diode intermediate sprag
• All-new thrust washers
• New OEM steel pan

This isn’t a rebuild—it’s a re-engineered, performance-first, reliability-focused transmission system.

Who This Transmission Is For

• SBF-powered street cars
• Restomods
• Street/strip builds
• Weekend cruisers that still want hard pulls
• Daily drivers requiring reliability
• Builders who want Bowler-level consistency and quality

If you want cheap, this isn’t it.
If you want dependable, dyno-tested performance you never have to think about, this is exactly what you buy.

Lead Time

Approx. 4 weeks for assembly and dyno testing.

Fitment Notes

• Specifically designed for Small Block Ford engines
• Will NOT fit FE, big block, modular, or Coyote engines
• Mechanical speedometer output available—contact us
• Use with recommended Bowler Tru-Street Installation Package or equivalent components

** We recommend our Tru-Street Installation Package or you can source all of your own installation items

Install Guide