The New 1970 Chevy Nova Big Block
From the September/October 1969 Chevrolet Service News
page 28
400 Cu. In. Engine Released for
1969 Camaro and All Past Model 396 Cu. In. Engine Service
The new 400 cu. in. Mark engine, introduced for the 1970 Monte Carlo, Chevelle, and Nova, has been released to replace the 396 cu. in. engine options for the 1969 Camaro and to service all past model 396 cu. in. engines.
For the 1969 Camaro, the 400 cu. in. engine assemblies will be identified in production using the same engine code letters used to identify the comparable 396 cu. in. engines except that the engine code letters will be preceded by the letter "C". The engine code letters are stamped on a pad which is located immediately forward of the right-hand cylinder head.
Production engine identification for the 1969 Camaro 396 and 400 cu. in. engines, then, is as follows:
SUFFIX 396 CU. IN. |
SUFFIX 400 CU. IN. |
ENGINE/OPTION APPLICATION |
| JB | CJB | L35 |
| JF | CJF | L34 |
| LG | CJG | L35 W/RPO M40 |
| JH | CJH | L78 |
| Jl | CJI | L34 W/RPO M40 |
| JJ | CJJ | L89 |
| JL | CJL | L78 W/RPO M40 |
| JM | CJM | L89 W/RPO M40 |
| JU | CJU | L35 W/RPO MA6 |
| KA | CKA | L34 W/RPO MA6 |
| KC | CKC | L78 W/RPO MA6 |
| KE | CKE | L89 W/RPO MA6 |
The new 400 cu. in. Mark engine cylinder block (NOTE: Do not confuse the 400 cu. in. Mark engine with the lighter block 400 cu. in. engine available as RPO LF6 on Chevrolet and Monte Carlo models) is identical to the 396 cu. in. block except for the bore which has been increased by .032 inch. This new block will replace all 396 cu. in. engine blocks in service. Any 1965-69 396 cu. in. engine block which requires replacement, therefore, must be replaced with the new 400 cu. in. block in either partial engine or fitted cylinder block form. All external attaching parts from the 396 cu. in. block can be used on the new block using the newest gasket sets. The new 400 cu. in. engine external attaching parts (cylinder heads, intake manifold, etc.) cannot be used on the 396 cu. in. engine in service. All internal parts (crankshaft, pistons, rings, etc.) will be retained in service, however, for the 396 cu. in. engine.
Service engines with the 400 cu. in. displacement can be identified by noting the letter "O" in the service serial number. This number is stamped adjacent to the engine production code number on a pad which is located on the case immediately forward of the right-hand cylinder head.
From the September/October 1969 Chevrolet Service News page 28
| ENGINE | VEHICLE | ||||||||
| Disp. and Type | Carb. | RPO | Comp.Ratio | HP/RPM | Fuel | Chevrolet | Chevelle | Monte Carlo | Nova |
| 153 L-4 | — | 8.50:1 | 90 @ 4000 | Reg. | X | ||||
| 230 L-6 | 1-bbl. | — | 8.50:1 | 140 @ 4400 | Reg. | X | |||
| 250 L-6 | 1-bbl. | L22 | 8.50:1 | 155 @4200 | Reg. | X | X | * | |
| 307 V-8 | 2-bbl. | — | 9.00:1 | 200 @ 4600 | Reg. | X | X | ||
| 350 V-8 | 2-bbl. | L65 | 9.00:1 | 250 @ 4800 | Reg. | X | * | X | * |
| 350 V-8 | 4-bbl. | L48 | 10.25:1 | 300 @ 4800 | Prem. | * | * | * | * |
| 400 V-8 | 2-bbl. | LF6 | 9.00:1 | 265 @ ** | Reg. | * | |||
| 396 V-8 | 4-bbl. | L34 | 10.25:1 | 350 @ 5200 | Prem. | * | |||
| 396 V-8 | 4-bbl. | L78 | 11.00:1 | 375 @ 5600 | Prem. | * | |||
| 396 V-8 | 4-bbl. | LS3 | 10.25:1 | 330 @ ** | Prem. | * | |||
| 400 V-8 | 4-bbl. | L34 | 10.25:1 | 350 @ 5200 | Prem. | * | |||
| 400 V-8 | 4-bbl. | L78 | 11.00:1 | 375 @ 5600 | Prem. | * | |||
| 400 V-8 | 4-bbl. | LS4 | 10.25:1 | 345 @ ** | Prem. | * | |||
| 454 V-8 | 4-bbl. | LS5 | 10.25:1 | 390 @ ** | Prem. | * | * | ||
| 454 V-8 | 4-bbl. | LS6 | 11.25:1 | 450 @ ** | Prem. | * | |||
X Base Engine (I added the red X since this engine was available on the 1970 Nova)
* RPO Engine (I added the red * since this engine was available on the 1970 Nova)
** RPM Value Not Available at Time of Publication