how would i tell what timing tab i need?

[ocbaud]

the following is my the Professional Products page about their balancers.

Small block Chevy - These engines have used three different timing pointer locations. Pre '69 engines have the TDC mark 2° to the left of the keyway centerline. The '69 to '85 dampers have the TDC mark 10° to the left of the keyway centerline. The 1986 to 1991/1992 have the TDC mark 40° to the left of the timing mark. All of our SB Chevy dampers, as well as all other aftermarket dampers, use the 10° TDC position. Our 6.75" diameter models have two TDC marks, one that is 10° and one that is 40° to the left of the timing mark. If you have a pre '69 vehicle you can use one of the aftermarket bolt-on timing pointers to align correctly with the timing marks on our dampers.

my engine is from a 71' vehicle. I'm using the following timing pointer:
http://www.jegs.com/cgi-bin/ncommerc...91&prmenbr=361

which mounts like this:
http://www.ocbaud.com/pictures/engine/3501.JPG

and yes, i just ordered a tdc finder thing from jegs