Tune up tip

[crazy longhorn]

I wont say all, but most of the HEI dist that I have been into have approx 20 degrees of mechanical advance in the dist, & the springs are very stiff bringing the advance "all in " rather high in the rpm range. They also have way too much vac advance for a perf engine. As far as adjusting the curve, you can change weights & springs for a faster curve, but adjusting the total amount of advance usually requires welding or filing the slots. I use a crane adjustable vac can, & the springs that come with it to alter the curve. my combo seems to like a 34 degree total(checked with the vac can unhooked & plugged). it also starts quicker @ a 8-10 degree initial setting.......8 initial+26 mechanical gets me to the total. The springs let me run "all in " around 2800 rpms......faster curve, & better responce. This also requires cutting back the vac advance, so she doesnt spark rattle under a low rpm load, such as pulling a hill. the stock settings work well for what the factory designed the truck to do, but high comp, hotter cams, & bigger carbs all affect the timing needs of the engine( intended usage, & driving habits). I honestly dont beleive a factory curve is optimum for any engine, it is very conservative & set up for the worst of conditions on a daily driver/hauler. IMO, a good curve will do wonders for even a "stocker" crazyL