The early outside plug 250 series engines used a small carbon brush assembly to activate the cooling fan clutch. This is a pencil-sized plastic assembly, held in place by a spring clip, with a small spring-loaded carbon brush that sends an electrical signal to activate a magnetic clutch to engage the radiator cooling fan. The design was improved on the later 250 cars with the addition of a second ground brush. The earlier assembly is shown on page 285 of Dick Merritt’s book Ferrari:Operating, Maintenance, and Service Handbooks 1948-1963. The later configuration, with the ground brush, is shown on page 170 of the “Carbooks” 275 Manual reprint. Ground Brush, the correct carbon brush and spring
When the new “outside plug 250 engines” were introduced Ferrari changed to the more modern spin-on type filters, again from the FRAM Company. These filters include the silk-screened sticker with correct information on the outside plug engines.
Ferrari used the Button type grease fittings on all of the cars prior to the 275 series which began using the more familiar “Allamite” type. On the 250 series cars the tie rod ends used the “Allamite” type grease fittings. This pull-on type adapter is appropriate for other Italian, French and English cars using the button type grease fittings with the head dimensions of 15mm across the flats and 2mm thick. Pull-On Type Grease Gun Adapter
For the long distance races or others when there would be a chance for rain Ferrari would use rubber boots to cover the distributors to keep the rain water out of the electrics. There are good photos of the T.R.s using these boots at Le Mans. Small Distributor Boots for the Front – Mounted Distributors