If you’ll recall a few years back, our friends at Ford Performance debuted a new high-performance iteration of the 4.6-liter-based modular engine block, which has now been made available to Blue Oval enthusiasts. Dubbed the 5.0-liter Modular Iron Boss Block, Ford actually offers this block in two separate configurations – both a bare block and a FRPP prepped short-block for all Two-, Three- and Four-Valve 4.6-liter applications. Suppliers like our friends at Brenspeed utilize these engine blocks for its own custom short-block builds, as shown in today’s video.

The blocks, which are comprised of cast iron, feature a much larger 3.700-inch bore (compared to the OEM 4.6-liter’s 3.552-inches) and can accommodate a much larger stroke, bringing it to 5.3-liters of displacement. It’s an excellent foundation for any high-performance 4.6-liter-based build, as Brent White of Brenspeed explains in the video above.

This is where the magic happens at Brenspeed.

This is where the magic happens at Brenspeed.

“Ford Performance for years has made great quality blocks,” Brent White, owner of Brenspeed told us, when asked what makes these engine blocks more favorable over their aluminum OEM counterparts.

“They are the starting foundation for our Brenspeed custom engines. The quality has surpassed our expectations, and when combined with the proper machine work and high quality parts, you end up with a great short block. We have always designed our engines for street use as well as track use. The Boss block has shown over the years it can handle pretty much whatever we throw at it. To date, we have never split, broken or cracked a block – and that says a lot when you consider all of the high horsepower Mustangs we build,” he concluded.

Keep an eye out in the future, and we may just use one of these engine blocks in our ’05 Mustang GT project car!