105/115 Berlina Rear Springs

[Kevin Charles Trent <trentkc@domain.elided>]

I have had several 1750 and early 2000 (stainless steel bumpers) Berlinas
and all had the yellow "FRAM 41" stickers on their rear springs.  When I
purchased a late ('74) 2000 Berlina parts car with the rubber bumpers, the
rear springs had a different yellow tag on the rear springs - "FRAM 42".
These FRAM 42 springs are the same height as the FRAM 41, but have about
1/4 additional coil on  the spring.  The. 42s used an alumium spacer at the
top of the spring that the 41s did not have.

Here is my question:  I'm installing the LSD rear axle from the '74 parts
car into my '71 Berlina.  I'm considering using the FRAM 42 springs, with
the assumption that they will probably carry more weight than the FRAM 41s.
 The '71 hauls heavy loads and pulls a boat, so I need as much spring a I
can get.  My assumption is based on the theory that the last of the 115
Berlinas  were loaded up with significantly more weight than the earlier
Berlinas.  Aside from the (extremely) heavy rubber bumpers, the chassis
also included lots of new chassis reinforcing steel in all the doors and
encircling the trunk.  (These crash protection reinforcements were also
located high in the chassis to the detriment of the roll center.)  Anyway,
I'm hypothesising that the factory had to put on heavier springs to deal
with the inceased weight of the later cars.  Alternatively, the extra 1/4
coil was just an addition to make the spring more progressive and produce a
smoother ride.  I  do not plan to use the spacers, because I don't want to
raise the rear ride height.  Does anyone have any insight to the difference
between these two springs?

KCT
Knoxville TN


  

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