Looking for clarification here - there are a number of different Porsche part numbers listed for front Bilstein struts used on 911's from 1971:

911 341 943/4 00 ('71-'72)

911 341 041/2 33 ('73)

911 341 079/80 36 ('74-'76)

911 341 041/2 30 ('74-'76) 'Sport' ?

911 341 041/2 31 ('77-)

What are the differences between these struts ?

Are they interchangeable ?

My '69E (originally fitted with hydropneumatic front struts) currently has Koni front struts (with alloy 'S' calipers) & rear shockers - would there be any (significant) advantage in swapping to Bilsteins ?

I know that the rear suspension was modified at some point (1972/3?) to alter the angle of the shocks & again around '76 (?) when I think the lower mount was changed to a smaller size.

Does anyone know if all pre-'76 rear shocks will fit my '69 model or are there differences ?