For 1970, Mustangs were slightly revised versions of the 1969 models. The biggest change was the return to single headlights. They were located inside the new, larger grille opening. Simulated air intakes were seen where the outboard lights were on the 1969 models. The rear was also slightly restyled. There were flat taillight moldings and a flat escutcheon panel, taking the place of the concave panel and lights used in 1969.
This year the famous 351 CID “Cleveland” V-8 engine was introduced two-barrel and four-barrel configurations. The 428 CID “FE” continued to be the performance powerplant with only the Boss 429 using the newer “385” series block.
The Boss 429 ran a unique set of cylinder heads on the 385 Series block. Where the Cobra Jet 429 engine was a upgraded version of the canted valve engine introduced on the 1967 Thunderbird and later 460 Lincoln, The Boss 429 heads were pure racing equipment – fitted to the Mustang to homologate it for NASCAR.The Boss 429 ran a unique set of cylinder heads on the 385 Series block. Where the Cobra Jet 429 engine was a upgraded version of the canted valve engine introduced on the 1967 Thunderbird and later 460 Lincoln, The Boss 429 heads were pure racing equipment – fitted to the Mustang to homologate it for NASCAR.