Building a Baby Max Wedge 435 Mopar B-Block Stroker That Makes Nearly 600 HP

Chrysler has a great tradition of producing powerful high-performance engines. Engines that you can build today.

We’re working with the Chrysler B-Block, which is the original low-deck version of the 413/426/440 c.i.d. RB-Block V8 engines that has gotten Dodge and Plymouth great respect through the decades. The B-Block, produced in 350, 361, 383, and 400 cubic-inch displacements, was introduced in 1958 to replace the Firepower Hemi engines.

The B-Block also replaced the “Poly” block V8, which was a more economical alternative to the Hemi from a manufacturing standpoint, which had polyspherical combustion chambers.

Chrysler would find the “Poly” chamber A-Block engines just weren’t the solution to the more complex Hemi powerplant, which was when engineer Robert S. Rarey went to work birthing the all-new B-Block in the mid-1950s.

The B-Block had to accommodate a 3.750-inch stroke with a 9.980-inch deck height, and later—a raised deck version of the B-Block, the RB-Block with a taller 10.725-inch deck height for those big-inch Mopars.

This engine sported a deep skirt bores and a five-bolt cylinder head pattern around each cylinder for greater cylinder sealing with five main bearings down under. It also had a new cylinder head design with short exhaust port runners for improved heat transfer into the water jackets. Shaft-mounted stamped-steel rocker arms weighed less and took less manufacturing time.

Rarey also decided to move the distributor and oil pump to the front of the engine for easier access both in manufacturing and service.

The 350-inch B-Block was a one-year-only engine—1958—and got very little notice.

The larger 361 c.i.d. B-Block stayed the course well into the mid-1960s. In 1959, Chrysler grew the 361 to 383 c.i.d., which would remain in production until 1972.

In 1972, Chrysler grew the 383 to 400 c.i.d., which had a larger 4.340-inch bore. A lot changed that year, with a lower compression ratio and hardened exhaust valve seats the following year for use with lower-octane unleaded fuels.

Although performance expired in the 1970s amid auto insurance rates and increasing government emissions mandates, Chrysler kept its foot in it for as long as it could with the big-cube 400 and 440 until production ended in the 1970s.

We’re convinced the low-deck B-Block has never gotten the credit it has deserved in terms of real performance.

Seems everyone wants the RB-Block. Although the RB deserves credit for knocking down the competition in a wide variety of racing venues, the B-Block weighs less, is cheaper to get, and it makes a great stroker long on displacement.

But it isn’t always easy to find. If you remember the sexy 383 Roadrunners, ‘Cudas, Super Bees, and Challengers not to mention Fury and Polara police interceptors, you know what the 383 can do.

Imagine what the 383 could do with more stroke and displacement.

Main Street 383-powered Mopars were a force to reckon with back in the day because they always won and there’s a reason why. They have good bones and great architecture from the pan to the intake. They were born at Chrysler to make power. And, they made a lot of it.  

The raised-deck 413/426/440 c.i.d. RB 10.725-inch deck height helps it accommodate a 4.500-inch stroke crank. The low-deck 383/400 B-Block makes up for its shorter 9.980-inch deck height with a super-size 4.30 (383) 4.340-inch (400) standard bore.

RBs can be stroked to 543 c.i.d., while even a low-deck 383/400 block can reach 512 c.i.d. if you want to take it that far.

We’d like to see what we can do with a 383/400 block, a Scat/Summit stroker kit, and tricked-up factory castings.

Because Gregg has extensive experience as a racing engine builder and professional cylinder head porter, he understands what needs to be done with B/RB-Block heads to get power. Flow bench numbers don’t lie, and Gregg is about to prove it out with our 426/435-inch B-Block. Gregg has taken a pair of 1967 vintage 383 head castings and CNC-ported them plus performed his own hand port and bowl work to get great flow numbers from the B-Block heads.

“It took a full five years of on-track and dyno testing to get these factory castings to flow like this,” Gregg said. “It is remarkable what you can do with these B-wedge heads.”

We’re going to take this vintage Mopar 383 and turn it into a 435 incher with support from Crower, Scat, and Summit Racing Equipment—a great support team. This 383 has been bored .040-inch to clean up the bores and get 435 c.i.d. Let’s get started.

Piston Ring End Gaps

Flow Bench

The stock Chrysler 383 head, circa 1967, sports a 208cc intake port. Gregg has two levels of Chrysler head porting. Stage 2 yields a 219cc intake port. Stage 3 is an all-out race head with a 228cc intake port. His routine includes CNC port and bowl work and unshrouding the intake and exhaust valves along with cleaning up the chambers.

The power our 383 turned 435 made was remarkable considering what we had for heads. Gregg went to larger 2.19/1.81-inch valve sizing and opened up the ports. Heads, coupled with a hot Crower roller hydraulic cam and greater bore and stroke took a 340-horse stocker to 562/552 horsepower/torque, which is impressive for stock castings.

Gregg has achieved good numbers from this engine along with a broad torque curve. What this means for you is excellent street power that will perform quite well at the track. We could get even closer to 600 horsepower and 600 ft/lbs of torque with a hotter cam. However, we wanted good street manners and tolerable idle quality at the traffic light.