ALL 318s poly or LA cast or forged are internally balanced.


Some time in production of the poly 318 the starter hole was changed. I was putting a 318 poly in a dart with a 318 LA and got it all in there and the starter would not go in. I don't remember what the difference was or if I could have just used the older starter but I didn't have on to try so I dropped a 273 in that I had on the other side of the shop. I think the motor I was trying was a 64 from a polara 4dr.

The poly has good combustion chamber shape, OK intake ports and very good exhaust ports. There are a few cam available, TTI makes headers weind intakes, and whatevr stroker kits fit in 318LAs will fit in them. Since the valves are closer to straight up and down piston to valve clearance should not be a problem. I have heard of guys going all the way to 340 size bores with them but I would get a very reputable sonic tester to test it first, even if they all could go 4.040 bore when new (not) they are 40plus years old and have corosion in them reduceing the maximum over bore. You could make a very stout 390 something stroker with them. Put in a good cam intake and port work on the intake side of the heads and it will make a killer sleeper

450hp and 500tq is not out of the realm of reality.