without running the nymbers how can you tell a 305 from 350
 

without running the nymbers how can you tell a 305 from 350

A 350 HAS A 4" BORE,NOT SURE HOW MUCH SMALLER A 305 IS.IF THE HEADS ARE OFF YOU CAN MEASURE IT

If it is all stock the timing mark on the balancer is close to center on the top..you have to set the timing behind the water pump looking down at the balancer instead of off to the side at the 2 o-clock position.
Also seems to me most 305's have a passanger side dip stick...and the balancer is kinda wide but hollowed compared to a 350's solid style balancer..

Why would the balancer be different? The crankshafts are the same.At least I think they are.

On some of the later engines, GM changed the zero mark on some of the balancers to use timing marks in the center of the timing cover behind the water pump. There are several versions of the balancer and tabs, so it is best to always check TDC when assembling. If you look at the keyway slot in the balancer and rotate it to about 2 o'clock, the TDC mark will be at about 12 o'clock on ones that need the tab welded in the center of the timing cover. The others will have the TDC mark closer to the keyway tab. But, I have seen this on 305's and 350's and both 305's and 350's had the dipstick tube on the passenger side.

So, the only way that I could tell for sure was to run the numbers off of the block on the drivers side rear where it bolts to the transmission.

Bill M