Need some help. I just recently purchased a 64 500xl 4dr. For some odd reason, there is no harmonic balancer on the original 390. I can't obviously check the timing with no marks at all. Engine runs fine, but with no balancer, I'm thinking it's a ticking bomb. Any suggestions on replacement balancers, whether I should strip down the block, or anything else I should look for? When I say the engine runs fine, no smoke out the pipes, no misfires, no taps or knocks. I'm going to dig into it a little (change cam, and the obvious that comes with it), but I really don't want to mess with the bottom end if I don't have to. Any info would be great, I'm fresh meat in the big block world, and even more with early 60's fords. This is what I know of what I got: 390FE single 4bbl Ford carb, cruisematic trans, 3.00 gears in a 8.8? or 9"? rearend. Everything with the car is original, including the large rust holes. I'd like to swap heads, intake manifold, cam, trans, and gears. Yet, again, to start, maybe a balancer would do me some good.