Mild 318 pinging
Compared with the timing on '67 273 with 4 bbl and 10:1 compression, the mechanical advance you have is in the same ballpark, up to 2000 rpm. Maybe even a little higher in the rpm if the inital was set higher than the 10* at 650 rpm.
My first question when reading your first post was about the 2000 rpm at 55 mph.
I generally use a rule of thumb of 3000 rpm for 60 mph. Now that's with 3.23 or thereabouts and close to stock tire diameters. Have you done the math to be sure its just 2000 rpm at 55 mph?
That would seem to really lug the engine, especially with a stock converter and hot cam.
So differences between your engine and the 67 high performance 273 that will effect timing it needs are compression, fuel octane, and maybe load as well.
Initial of 10 to 14* is perfectly reasonable. 26* a 2000 rpm may be too much, and 32 at 2600 rpm is certainly way too much with vacuum advance. it may be OK without vac advance but with the really load and low octane fuel, I dont know.
Compared with the timing on '67 273 with 4 bbl and 10:1 compression, the mechanical advance you have is in the same ballpark, up to 2000 rpm. Maybe even a little higher in the rpm if the inital was set higher than the 10* at 650 rpm.
My first question when reading your first post was about the 2000 rpm at 55 mph.
I generally use a rule of thumb of 3000 rpm for 60 mph. Now that's with 3.23 or thereabouts and close to stock tire diameters. Have you done the math to be sure its just 2000 rpm at 55 mph?
That would seem to really lug the engine, especially with a stock converter and hot cam.
So differences between your engine and the 67 high performance 273 that will effect timing it needs are compression, fuel octane, and maybe load as well.
Initial of 10 to 14* is perfectly reasonable. 26* a 2000 rpm may be too much, and 32 at 2600 rpm is certainly way too much with vacuum advance. it may be OK without vac advance but with the really load and low octane fuel, I dont know.
