B / RB Engine Blocks

Chrysler's "B" and "RB" engine blocks are extremely sturdy. The block casting  uses extensive support webbing in the mid and lower areas. The main bearing bores are supported by the  block sidewalls which extend past the crank centerline more than 2 inches. Additional webbing to support the main bearing bores make the block very rigid without excessive weight. Bare block castings weigh in at about 215 pounds for the "B" engine and 225 for the "RB". The primary differences between the "B" and "RB" blocks are the main bearing bore diameters (2.625 for the "B", 2.750 for the "RB") and the crank centerline to deck surface dimensions (9.980 for the "B" vs. 10.725 for the "RB"). Rod journals are the same for both engines.

Interchange between the engines is exceptional. Both use the same 4.80 inch bore spacing and the same cam to crank spacing. The heads, timing chain, camshaft, oil pan etc. interchange completely. Intake manifolds don't interchange due to the difference in deck heights.

CID

Bore

Stroke

Series

350

4.060

3.380

B

361

4.120

3.380

B

383

4.250

3.380

B

400

4.340

3.380

B

383

4.030

3.750

RB

413

4.120

3.700

RB

426

4.250

3.750

RB

426

4.250

3.750

RB

440

4.320

3.750

RB

Engine Block Stamping #

On "RB" engines the cubic inch displacement is stamped on a pad located at the front of the block. "B" engines have a similar pad located on the right side of the block near the base of the distributor.  Engine displacement, performance level, undersized bearing journals, oversize cylinders and other special information are also identified here.

Decoding Engine Block Stamping #'s

1960-1964 

From '60 to '64 a typical engine ID code will look like this: S42-222
The first digit identifies the year: S=1962
The next 2 digits are the first 2 digits of the engine CID: 42=426
The last 3 digits are the date and month: 222= February 22

1965 - 1971

In '65 the third digit of the CID was added to the engine ID  code. 
After '65 a typical engine ID code will look like this: B383-322
The first digit identifies the year: B=1966
The next 3 digits are the engine CID: 383=383
The last 3 digits are the date and month: 322= March 22

Year Codes for B & RB Engines

• A - 1965

• B - 1966

• C - 1967

• D - 1968

• E - 1969

• F - 1970

• G - 1971

• H - 1972

• J - 1973

• P - 1960

• R - 1961

• S - 1962

• T - 1963

• V - 1964

• 4T - 1974

• 5T - 1975

• 6T - 1976

• 7T - 1977

• 8T - 1978

Other Stampings
Additional stampings may be found on the ID pad.
They identify non standard engine components. 

A - .020 oversize cylinder bores

Diamond - oversize tappets

E - Cast Crankshaft

HP - High Performance

L or LC - low compression

M - .001 undersize main bearing journals

Maltese Cross - .001" undersized bearing shells

Maltese Cross and an X - .010" undersized crankshaft

O.S. - .005 oversize valve stems

P - premium fuel

R - regular fuel

RX or MX - all main or rod journals .010" undersized

S - special engine

WT or TW - water test

X - .010" undersize crankshaft

'68 and later B&RB engine serial numbers

Beginning in 1968 all Mopar B&RB engine blocks have an engine serial number stamped in the left side oil pan rail at the rear corner under the starter opening.

Sample Serial # PT44028650001

 Plant Code: PT

• MV,MN - Marysville Plant (426 Hemi)

• PT - Trenton Plant (361, 383, 400, 413, 426, 440)

Cubic Inch Displacement: 440

• Should need no further explanation

Date Code: 2865

• Based on 10,000 day Julian Calendar

• 2865 is June 1, 1969

Serial Number: 0001

• A sequential number for each days
  production beginning with 0001

Matching Numbers?

On 1968 and later engines the numbers stamped on the lower rail of the engines right (passenger) side match the last 8 digits of the cars vehicle identification number. This confirms that this is the original engine. The matching numbers add to the cars value.

Engine Block Casting # and Date Code

The date code and block casting numbers are found on the left side of the block. This block bears the casting # 2536430. The following chart identifies it as a 66 - 72 440 block. The casting date of 2-26-69 indicates that this is a '69 block.

B / RB Engine Block Casting #'s

Casting #

Application

Type

Engine

1944929

Chrysler - Dodge - Plymouth

B

58 350

1737629

Chrysler - Dodge - Plymouth

B

61-64 361

2205712

Chrysler - Dodge - Plymouth

B

58-66 361

1851729

Chrysler - Dodge - Plymouth

B

59-64 383

2120329

Chrysler - Dodge - Plymouth

B

59-64 383

2468130

Chrysler - Dodge - Plymouth

B

59-71 383

3614230

Best 400 Block - Heavy  Main Webs

B

71-72 400

3698630

Chrysler - Dodge - Plymouth

B

73-78 400

1852029

High Performance & Truck

RB

62-413

2120529

Chrysler - Dodge - Plymouth

RB

59-65 413

2205697

Chrysler - Dodge - Plymouth

RB

59-65 413

2205697

Chrysler - Dodge - Plymouth

RB

64-426

2406730

Max Wedge

RB

63-65 426

2532230

Max Wedge

RB

64-66 426

2658836

Industrial

RB

2536430

Chrysler - Dodge - Plymouth

RB

66-72 440

3698330

Chrysler - Dodge - Plymouth

RB

73-78 440

4006530

Chrysler - Dodge - Plymouth

B

76-78 400

4006630

Chrysler - Dodge - Plymouth

RB

78 440

Big Block Cylinder Heads

Since 1958 there have been 14 different head castings. All B/RB heads interchange which makes swapping easy. However, swapping the '62 to '64 Max Wedge heads onto a "B" engine isn't recommended because there are no intake manifolds available for that combination.

The '67 440 and '68 to '70 383 and 440 4-barrel heads are considered the best factory heads. The '67 heads have a smaller "closed" combustion chamber and can be used to increase the compression ratio on later model low compression engines. Care must also be taken when swapping the '67 heads onto the '68-'69 383 due to the lack of piston to chamber clearance. The 383  has a positive deck height. (the piston protrudes above the  block deck surface) The deck height has to be at or below the deck surface to provide the necessary clearance.

Location of Cylinder Head Casting #'s

The casting numbers for Mopar Big Block cylinder heads can be found on the underside of the head on an intake runner. (upper photo)

The casting number can also be found under the valve cover on an intake runner. (lower photo)

Big Block Cylinder Head Part #'s

Casting#

Part#

Engine

Chamber

In 

Ex 

1737637
1944705

2128533

58-59 361

Closed

1.94

1.60

1737637

2448752

60 361/383

Closed

1.94

1.60

2206324
2206924

2128589

61-62 361/383/413

Closed

2.08

1.60

2402286

2402358

62 413 Max Wedge

Closed

2.08

1.88

2463209

2406754

63 426 Max Wedge

Closed

2.08

1.88

2463200

2448752

63 361/383/413

Closed

2.08

1.60

2406518

2406736

64 426 Max Wedge

Closed

2.08

1.88

2406516

2406732

64-67 361/383

Closed

2.08

1.60

2406158

2806019

67 440

Closed

2.08

1.60

2780915

2800762

67 440 HP

Closed

2.08

1.74

2843906

2843904

68-70 383/440

Open

2.08

1.74

2951250

2843904

68 440

Open

2.08

1.74

3462346

3462344

71-72 383/400/440

Open

2.08

1.74

3462346

3671640

73 400/440

Open

2.08

1.74

3751213

3751218

73 400/440
Motor Home

Open

2.08

1.74

3769902

3769910

74 400/440

Open

2.08

1.74

3769975

3769954

75 400/440

Open

2.08

1.74

4006452

3769954

76-78 400/440

Open

2.08

1.74

Pre '64 heads are easily identify because they use only 4 valvecover bolts.

Big Block Mopar Crankshafts

Chrysler's "B" and "RB" engine crankshafts have two basic stroke dimensions. The "B" engine crankshaft uses a 3.380 inch stroke and the "RB" engine uses a 3.750 inch stroke. Main journal size also differs between the "B" and "RB" engines. The "B" engine uses a 2.625 inch main journals, the "RB" uses  2.750 journals. Both engines share the same 2.380 inch rod journals.

All early crankshafts are steel forgings. In 1971 Chrysler used a cast crank in low performance 383 engines. The use of cast iron crankshafts in 440's began in 1972. All cast cranks and certain forged steel cranks are externally balanced. These require the use of specially balanced harmonic dampeners, torque converters and flywheels. The appropriate components  must be used to ensure that the reciprocating assembly is in balance. If an internally balanced crank is used with an external balanced converter or dampener (or vise- versa) a severe out of balance condition  will occur. Externally balanced crankshafts can be internally balanced by adding a heavy metal called Mallory metal to the crank throws. 440's equipped with 3x2 barrel carbs were also externally balanced to compensate for heavier rods. They require the use of externally balanced dampeners and converters or flywheels.

Big Block Mopar Crankshaft Part #'s

Part#

Engine

Material

Comments

2268114

383 4BBL

Forged

3462922

383 / 400 2BBL

Cast

Externally Balanced

3672000

400 4BBL

Cast

Premium Cast Crank
Suitable for mild hop-ups

2536983

67-71  440 4BBL

Forged

A good general crankshaft

3512036

70-72 440 6BBL

Forged

Externally balanced
premium crank

3671283

72-73 440 4BBL

Forged

A good general crankshaft

3671242

73 440 4BBL

Forged

Balanced for different
weight pistons

3751889

74 440 2&4 BBL

Cast

Externally balanced

3751899

74 440 HiPo

Forged

A good general crankshaft

2406240

413/426 Max Wedge

Forged

Best RB crankshaft

Big Block Crankshafts Dampers

Part#

Application

2658457

1958-1971 All B & RB engines

3512017

1970-1971 440 6BBL and '71 440 High Performance

3577180

1971 383 2 barrel (cast crank)

3614371

1972-1973 400 Forged Crank

3614374

1972-1973 400 Cast Crank

3614371

1972-1973 440 Standard Performance

3614372

1972-1973 440 High Performance

3577785

1974 440 Cast Crank

72 and up B&RB dampers use a different pulley bolt pattern.

Degree your damper

A degreed damper is useful for setting total spark advance and for valve lash adjustments when using a solid lifter camshaft. All Mopar crankshaft dampers have the same 7.25 inch diameter. You can mark your damper with a self adhesive timing tape or mark it yourself using the following dimensions.

Mark your damper in the direction of rotation (1/16 inch = 1°)

Degrees

Distance

Purpose

28°

1 3/4"

Setting Total Advance

30°

1 7/8"

32°

2"

34°

2 1/8"

36°

2 1/4"

38°

2 3/8"

40°

2 1/2"

42°

2 5/8"

103°

6 1/2"

Setting Cam Centerline

105°

6 5/8"

107°

6 3/4"

109°

6 7/8"

111°

7"

180°

11 3/8"

Setting Valve Lash

Big Block Connecting Rods

The connecting rods used in B and RB engines are of a typical I-Beam design. Other design features include pressed fit wrist pins and 3/8 inch cap bolts. Dimensions of the "B" and "RB" rods are similar with the exception of the center to center length. the RB rods are .410 inches longer. The rods have nearly the same cross-sectional area and use the same rod bolts but the b engine rod is capable of higher rpm abuse because a shorter beam area can tolerate greater loads. The shorter beam area and the reduced loads  of the B engines shorter stroke allow reliable operation in the 6500-7000 rpm range for stock rods. Due to higher loads induced by longer rods and crankshaft stroke, the RB rod should be limited to 6000-6200 rpm

 B Engine Intake Manifolds

Engine

Year

Comments

Casting #

383 2x4

59-61

1827899

383 4bbl

60-67

2205968

383 4bbl

68-69

2806301

383 4bbl

70-71

2951666

400 4bbl

72

3614046

400 4bbl

73

3671879

400 4bbl

74

3698442

400 4bbl

75-76

3830949

413 4bbl

59-65

2206000

413 2x4

59

300E

2264877

413 2x4

62

300H

2266487

413 2x4

62

Max Wedge / Aluminum

2402726

413 2x4

63-64

Crossram / Left

2421369

413 2x4

63-64

Crossram / Right

2421368

413 2x4

63-64

Crossram / 300J-300K Left

2129987

413 2x4

63-64

Crossram / 300J-300K Right

2129985

413 2x4

63

Max Wedge Stage ll Aluminum

2402728

413 2x4

64

Max Wedge Stage lll

2402720

 RB Engine Intake Manifolds

Engine

Year

Comments

Casting #

426 2x4

65

Max Wedge / Aluminum

2406185

426 2x4

64

Max Wedge / Aluminum

2465165

426 Hemi

66-71

Street Hemi

2780543

440 4bbl

66

2206000

440 4bbl

67-69

2806178

440 4bbl

70-71

2951736

440 4bbl

71

3512501

440 4bbl

71-72

3614014

440 4bbl

73

3698444

440 4bbl

74

3751721
3830733

440 4bbl

75-76

3830733

440 3x2

69

Aluminum

3412046

440 3x2

70

Aluminum

3418681

440 3x2

70-72

Iron

2946275
2946276

B&RB Engine Exhaust Manifolds

Engine

Year

Comments

Casting #

350-361

58

Right

2205535

350-361

58

Left

2205536

361

59

Right

1739599

361

59

Left

2205536

361

60-64

Right

2205535

361

60-64

Left

2205536

383

59

Right

1739599
2205535

383

59

Left

2205536

383

60-64

Right

2205535

383

60-64

Left

2205536

383

65

Right

2205535

383

65

Left

2461307

383

66-69

Right

2532464

383

66-69

Left

2461307

383

68-69

Cuda & Dart / Right

2863000

383

68-69

Cuda / Left

2899002

383

68-69

Cuda & Dart / Right

2863900

383

68-69

Cuda & Dart / Left

2946720

383

68-69

383 Magnum / Right

2806900

383

68-69

383 Magnum / Left

2843992

383

70-71

B&C Body / Right

2899879

383

70-71

B&C Body / Left

2951865

383

70-71

C Body / Right

2899879

383

70-71

C Body / Left

2951216

383

70-71

C Body / Right

2899970

383

70-71

C Body / Left

2951861

413

59

Right

1739599

413

59

Left

2205536

413

61

300G / Right

2205830

413

61

300G / Left

1947434

413

61-64

Right

2205535

413

61-64

Left

2205536

413

62

Max Wedge / Right

2402334

413

62

Max Wedge / Left

2402336

413

63-64

300J & 300K / Right

2402781

413

63-64

30J & 300K / Left

2402782

413

65

Right

2205535

413

65

Left

2463107

426

63-64

Max Wedge / Right

2402334

426

63-64

Max Wedge / Left

2402336

426 Hemi

64-65

Hemi / Right

2465657

426 Hemi

64-65

Hemi / Left

2468658

426

64-65

Right

2205898

426

64-65

Left

2203262

440

66-68

Right

2532464

440

66-68

Left

2461307

440

67

 440 Magnum / Right

2806900

440

67

440 Magnum / Left

2806974

440

68-69

440 Magnum / Right

2806900

440

68-69

440 Magnum / Left

2843992

440

70-71

C Body / Right

2899879

440

70-71

C Body / Left

2951216

440

70-71

B - C Body / Right

2899879

440

70-71

B - C Body / Left

2951865

440

70-71

C Body / Right

2899970

440

70-71

C Body / Left

2951861