Engine Summary
- Manufacturer
- Pontiac
- Family
- Pontiac large-journal Super Duty V8
- Displacement
- 421 cubic inches
Also Known As
1961 Pontiac 421 Super Duty1961 SD-4211961 Pontiac 373-hp 4211961 Pontiac 405-hp dual-quad 421
Engine profile
1961 Pontiac Super Duty 421 V8
Pontiac large-journal Super Duty V8 · 421 cubic inches · Pontiac
Identification reference
Engine Details
Source-backed component numbers, codes, stampings, and application notes.
Dual-four-barrel configuration
- Value
- Carter AFB 3435 front and 3433 rear; 405 hp at 5,600 rpm
- Application
- 1961 Super Duty 421 with manual transmission
- Type
- carburetor / part number
- Car pages
- 1961 Pontiac Catalina Super Duty 421
Single-four-barrel NASCAR configuration
- Value
- Carter AFB 3123S; 373 hp at 5,400 rpm
- Application
- 1961 Super Duty 421 dealer installation for single-carburetor competition
- Type
- carburetor / part number
- Car pages
- 1961 Pontiac Catalina Super Duty 421
Early 405-hp cylinder heads
- Value
- 540306 with 1.92-inch intake and 1.66-inch exhaust valves
- Application
- early-production 1961 405-hp Super Duty 421
- Type
- cylinder head / casting number
- Car pages
- 1961 Pontiac Catalina Super Duty 421
Sources: 1961 Pontiac Full Size Cars Fact Sheet , 1962 Pontiac Catalina 421 Super-Duty - Survival Of The Quickest
Bore, stroke, and compression
- Value
- 4.09375 x 4.00 inches; 11.0:1
- Application
- 1961 dealer-installed Super Duty 421
- Type
- engine assembly / specification
- Car pages
- 1961 Pontiac Catalina Super Duty 421
Sources: 1961 Pontiac Full Size Cars Fact Sheet , 1962 Pontiac Catalina 421 Super-Duty - Survival Of The Quickest
Valve train
- Value
- Mechanical lifters with 1.65:1 rocker arms
- Application
- 1961 Super Duty 421
- Type
- valve train / specification
- Car pages
- 1961 Pontiac Catalina Super Duty 421
Cars Using This Engine
1 linked car page.
Series 23 Catalina donor, typically a two-door sedan or bubble-top Sport Coupe, converted after delivery with Super Duty 421 equipment
1961 Pontiac Catalina Super Duty 421
Dealer or race-team installation after Pontiac assembly