I bought this truck from the original owner. With the paint job, it's almost back to showroom condition. Engine compartment needs a liitle sprucing, but that's not the current issue. I need some advice regarding the timing. The engine has 178k miles on it. After adjusting the lifters (3/4 turn past zero lash), carb. rebuild (manual choke) and replacing intake/exhaust manifold gasket, I got around to checking the timing setting. At idle it was 10 BTDC (at the "A" on the plate with vacuum advance blocked). When revved, the timing went off the scale. Is this normal? Timing was then set to 4 BTDC, but again, when revved the mark went off the scale! Is the mechanical advance s'posed to take it that far? Generally, the old 230 runs fine, but there is a little spark knock when running a steady 55 mph and some engine hesitation when accelerator is depressed. Also used the vacuum gage technique to check timing. Hooked it up to the intake manifold where the PCV ties in. Vacuum was a steady 18" Hg at idle and a slight advance brought it up to 20" Hg. But when the light was put on and the engine revved, timing advanced off the scale again! So, specifically, at idle, what should the timing be set at? Does the mechanical advance take it that far? Do I have a clue? Thanks.
