Quote Originally Posted by DennyW
You can buy the pre-stretched sets for 32.95, for small block chevys.

COMP Cams Magnum Double Roller Timing SetsPerformance and reliability for the street.
Building a really high performance street vehicle? COMP Cams Magnum double roller timing sets are built for maximum performance on the street. They have heat-treated, pre-stretched, large-pin, double-row chains for extra strength and reliability. They also have crank sprockets with three keyways, which allow you to set cam timing at 4 degrees advanced, 4 degrees retarded, or normal. In addition, all Magnum double roller timing sets are dynamically balanced for smoother operation.

http://store.summitracing.com/egnsea...1&autoview=sku
What Denny say's is true.
One thing I might add is "crank timing" is not the same as "cam timing" in other words I would check all piston to valve clearance's and re-degree the cam when or if you decide to move the crank sprocket around.