SBM Distributor overhaul DIY?
Maybe this will help you visualize the situation you had.
Here's a sketch of what the timing on your engine might have looked like.
A distributor with a curve like this would be typical for an engine where the initial timing was 5*BTC or less!
If this is the case, changing the initial tension isn't really going to help.
Need to shorten the slots.
My preference is to weld the insides of the slots - the reasons why are covered in the thread with Rock able.
You can try the FBO plate. I don't know how well it will work with the angled slots. I assume he's provided enough width. If it has some slots in it that shorten the inside more than the top, that would be best. Then try it with the factory springs first.
If you're never going to run vac advance, then a pretty long primary curve like sketched here will be OK.
If using vac advance, need to let the secondary spring engage at lower rpm.
Maybe this will help you visualize the situation you had.
Here's a sketch of what the timing on your engine might have looked like.
A distributor with a curve like this would be typical for an engine where the initial timing was 5*BTC or less!
If this is the case, changing the initial tension isn't really going to help.
Need to shorten the slots.
My preference is to weld the insides of the slots - the reasons why are covered in the thread with Rock able.
You can try the FBO plate. I don't know how well it will work with the angled slots. I assume he's provided enough width. If it has some slots in it that shorten the inside more than the top, that would be best. Then try it with the factory springs first.
If you're never going to run vac advance, then a pretty long primary curve like sketched here will be OK.
If using vac advance, need to let the secondary spring engage at lower rpm.