67 Chevy, 350, edelbrock 650, 700R4, and 3.73 rear. 13 city. near 16 highway. Truck DID have a 250 I6 with manual 3 speed. I think I got around 13mpg. Not to mention top speed was about 70 and the rpms were around 4500. OH, did I also mention that the motor was WAY underpowered and SUCKED??? They're cool trucks. I'd say to heck with it and leave it alone. You'd be messing with mounts, driveshaft shortening/lenghtening, wiring, throttle cables, cluthes or TV cables...leave her alone man....ENJOY IT. SIX BANGERS ARE NOT FUN! As for the 305 the reason they do better on gas is the pistons are way smaller than a 350 and they produce about 50 hp less and much less torque than a stock 350. I spent about a grand converting my truck from a six to a V-8. I WANTED the v-8 so it was worth it to me. I can't see saving a couple dollars a week in fuel worth losing tremendous power and all the work and money it will cost to convert. Not to mention it's a lot of work and a pain in the
