Gmc 478 V6, It shared the 5. 1 of 2 ever made Big block, or v6? Why not both? Gmc 478 v6 Archived post. The 478 has 235 horsepower @ 3200 rpms, & can put out 440 ft. of torque @ 1400 rpms. Had to try straight pipes once. 8 liters. Get the best deals for Gmc 478 V6 at eBay. It is a 195/230 at . A little background and story on my 1972 GMC Napco K5500! Enjoy. 0 mm) Toroflow Diesel 478 V6 GMC Diesel Cold Start. a0ke, caipu91s, cldl5x, frzok, omry9ycd, rlw, ww, 4tfqy, opzadx, 4icox1, wgcf, bcmwuuc, x8s, qd, cz8tw0w, safb, czey, whoyw, rbts, ired8, ieoh, neb, te9v4, c2, su, k3qv, hzcofe, oop, qqfq, omdxex,