the standard timing i 15 degrees btdc most people retime the motor to about 18-20 degrees...the way to do it is to get a timing light, connect the lead to no1 spark lead and point it at the crank pulley with the engine running. on the timing cover there its a little pointer and on the crank pulley there are lines that you will see. the fist one is usually yellow but it might have no color due to age. every mark after the first one represents 5 degrees.....just move it tile it on or near 20 degrees by loosening the slider bolt on the dizzy and turning it till the line is on the pointer and that's it(don't forget to tighten the bolt on the dizzy when you finish)
Click the scales.....you know you want to!!!!