I have a question..... I have never messed with the timing on my 72 riv 455 other then to check it. Stock motor, original distributor with a acell points eliminator. I was reading this thread so I started playing with the timing. Checked all the parts and both vacuum and mechanical advance were working properly. Fresh tuneup and carb is set well. Car ran very nice but I felt it was underpowered. Timing Was set a 4 degrees (factory for 72), bumped it to about 10. Immediately improved power.......so I ordered the crane kit as listed in the thread. Installed new springs (1 blue 1 yellow) per cranes paperwork that’s all in at 2600. Once again immediate power increase with a much stronger mid range. I’m pissed I didn’t do this along time ago! Car is no drag racer, I’m sure the rear end is a 2 something ratio and of course it’s a riviera so it’s heavy as heck So after all that......Should I go lower on the springs (silver silver all in at 2200) or would I be getting into idle timing? Would a stock 72 455 even benefit from a change at this point?