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-   -   305 crank in 350? (https://www.racingjunk.com/forums/showthread.php?t=20075)

chrishester1224 03-04-2008 01:32 PM

305 crank in 350?
 
I have a friend rebuilding a350 .Can a 305 crank be used ? Which balancer

ejf 03-04-2008 01:57 PM

I think 305 and 350 have the same stroke 3.48

chrishester1224 03-04-2008 02:42 PM

305 crank in 350?
 
yea, the stroke is the same the balancing is most of the concern. Should he use the 305 balancer or the 350?

sp2816 03-04-2008 03:45 PM

balancer
 
Both balancers are internally balanced, but you need to use the one that TDC lines up with the timing cover marks. Some have TDC at the 12 o'clock position and the cover has the tab welded on, while some are closer to the 2 o'clock position and have the bolt on tab.

It would be best to have the crank balanced to the heavier rods and pistons, but they do have the same stroke and are both internally balanced.



Bill

chrishester1224 03-04-2008 05:35 PM

305 crank in 350?
 
what if he uses an after market damper? Will the 305 rods work 2, just have the 350 pistons press on those rods????

Tod74 03-05-2008 05:07 AM

Re: balancer
 

Originally Posted by sp2816
Both balancers are internally balanced, but you need to use the one that TDC lines up with the timing cover marks. Some have TDC at the 12 o'clock position and the cover has the tab welded on, while some are closer to the 2 o'clock position and have the bolt on tab.

It would be best to have the crank balanced to the heavier rods and pistons, but they do have the same stroke and are both internally balanced.



Bill

I THOUGHT THE RODS WERE THE SAME ??? :? I have taken a crankshaft from a 305 and put it in a stock 350 with no issues.

I wouldn't argue with anyone about it but I thought small block chevy's only had three sized rods...5.7 large journal, the short 400 sb rod 5.565 or whatever it was, and then the small journal rods...which I THOUGHT were 5.7" .... :?

sp2816 03-05-2008 06:17 AM

The 305 and the 350 connecting rods have the same dimensions which are for the 2.100 crank pin and are 5.700" long, but over the years there have been a lot of different rods and they don't all weigh the same. There are some of the higher performance 350 rods (GM performance powdered rods) that are heavier and stronger.

If you are not going to have the engine balanced with the heavier pistons, then I wouldn't worry about the difference in the connecting rods. But, you do need to check TDC to verify that the mark on the balancer lines up with the timing mark pointer.

Bill


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