Quote Originally Posted by Littlechevy View Post
Hey guys I'm new here. I have a chevy 305 that is a little "different", an I would like to figure out some things. I've taken it to a mechanic and he timed it and tuned it but is still getting 12.5mpg.

I took a video of the exhaust because I have no idea what cam it is and was hoping someone could guess? Is this why my mog is terrible?

http://m.youtube.com/watch?v=tJqJ2-nz2-A

Again I bought the car and I have no idea what it has other than the moot or was rebuilt.
realy hard to tell what size the cam is by the sound out the exhaust .. when i do is i need to lay my hand on the air cleaner when the engine is running... but more numbers the better like vacuum at idle . a lower dollar cam kit and check valve springs and over all engine shape then recam it. the 305 may not be the best but far from worst yep a 350 or 383 may be better but there were a hell of a lot of the smaller 283 out there pulling big old chevys and boats . 350 or 383 not going to get better fuel MPG if your foot down in it