how to recurve timing?

|| I recently put a low compression engine in my '69 work truck and will ||need to re-curve the timing to provide more advance.It seems to want ||more initial advance too but how much? ||Is there a method for determining correct base timing?Believe it or ||not,the shop that put in the motor has no clue what the compression ||ratio ||is but I can tell it's no more than 8-1,and perhaps 7.5-1(I had ||specified 8.7-1 when ordering).Any help will be much appreciated due to ||current 10 MPG wallet drain crisis.

We used to time those old things by ear. I don't know of any reason why you could not still do that. Advance the base timing a little at a time until it doesn't want to start easily, then back off. As long as it doesn't ping, you are OK. If it pings, drop it back till it quits. You can't do much better than that for your purposes. I wouldn't go much past 15 deg initial. Centrifugal advance is a little more difficult. You set total advance by modifying the tabs that stop the advance weights. IIRC you would bend or file the tabs until you got the total advance you wanted. Again IIRC, a pro recurve would consist of limiting total advance, and making it come in quicker for more mid-range torque. I don't know if that helps, but there it is :) Texas Parts Guy

Thanks Rex ,that's exactly what I needed to know.I also have a collection of different distributor springs and I have an adjustable Vac- advance on there so I'll get to work on it Sunday.