The following year, the GC10 2000GT received a 2.0 L (1998 cc) L20 I6 engine like the Nissan Cedric instead of a Prince G-7 engine. The chassis was already designed to receive a straight six, to avoid the S54 extension problem. 105 hp (78 kW) was available from this new engine, in 1970 Nissan production Skyline 2000GT Automatic, in October 1970 Nissan introduced 2 Door Coupe.
Nissan Skyline KGC10 GT-X (L20 engine)
The first GT-R Skyline appeared in February 1969. Called the PGC-10 (KPGC-10 for later coupé version) internally and Hakosuka (ハコスカ) by fans. Hako (ハコ) means Box in Japanese, and suka（スカ） is short for Skyline (スカイライン; Sukairain). It used the 2.0 L (1998 cc) S20 I6. This new DOHC engine (which was designed by the former Prince engineers) produced 160 hp (118 kW, 180 N m), and was similar to the GR8 engine used in the Prince R380 racing car.
The GT-R began as a sedan, but a 2-door coupé version was debuted in October 1970 and introduced in March 1971. The cars were stripped of unnecessary equipment to be as light as possible for racing, and performed well at the track. The sedan racked up 33 victories in less than two years, and the coupé stretched this to 50 through 1972.
The C10 raced against many cars including the Toyota Corona 1600GT (RT55), Isuzu Bellett GTR, Mazda Familia (R100) & Capella (RX-2) – even Porsche. In late 1971 the new Mazda RX-3 became the GT-R's main rival. The GT-R managed a few more victories before the RX-3 ended the GT-R's winning streak.
1500 – 1.5 L G-15 I4, 88 hp (71 kW, 128 N m)
1500 – 1.5 L G-15 I4, 95 hp (71 kW, 128 N m)
1800 – 1.8 L G-18 I4, 105 hp (78 kW, 150 N m)
2000GT – 2.0 L L20 I6, 120 hp (90 kW, 167 N m)
2000GT-R – 2.0 L S20 I6, 160 hp (118 kW, 180 N m)
C-10 4-door sedan or 5-door wagon 1968
GC-10 4-door 2000GT 1969
PGC-10 4-door GT-R Skyline 1969
KPGC-10 2 Door GT-R Skyline 1970
KGC-10 2000GT-X 2-door 1971
KGC-10 2000GT-X 4-door 1972
HGLC10 2000/2400GT 4-door Left Hand Drive