1970 saw the introduction of the most powerful
ClassicChevelle SS
of all time.
Responding to the lifting of GM's ban on engines larger than 400 cid in midsize
cars, Chevrolet answered by using a new 454 cubic engine in its Chevelle SS.
The new 454 was known as the LS5 and packed 360bhp. The largest engine choice
was the LS6 version with 450bhp. The LS6 had a 800-cfm Holley four barrel on an
aluminum manifold, 11.25:1 compression, solid lifters, four-bolt mains, forged
steel crank and connecting rods, forged aluminum pistons, and deep-groove
accessory pulleys. Up to this time no production engine ever had a larger
factory horsepower rating. The standard Chevelle SS 396 continued with its 402
cid engines, although the 325bhp was dropped and the 350bhp version was now
standard. Optional on both the 396 and 454 was a new vacuum operated
cowl-induction hood, which had a rear facing door near the base of the
windshield to feed cold air into the engine. The styling was new with a "vee"
front end, functional hood pins, and five-spoke Rally wheels. This was truly the
pinnacle of the Chevelle SS performance.
