The 1974 Motion 454 Vega was a wild experiment by Joel Rosen’s Motion Performance: taking a super-light Chevy Vega and stuffing in a massive 454-ci big-block V8. To make it work, they cut back the firewall, used a “saddle-type” front mount (think ’62 Corvette style), and moved the stock crossmember rearward. With a fresh solid-cam 454, close-ratio 4-speed manual, 4.56:1 rear axle, and big rear tires on a narrowed 12-bolt, it ripped through every gear — launching off the line so hard it broke tir