Interesting info for some. Improvements during production on the 348. May have been posted somewhere here previously I'm sure, but hey. 1. 05/30/91 differential side sealproduction improvement 2. 05/30/91 Bosch starter motor changed to Nipponproduction improvement 3. 10/10/91 cam seal housing modificationreduced oil leakage 4. 10/10/91 double plate-clutch changed in favor of single-plate clutchproduction improvement 5. 10/10/91 new alignment specsimproved handling 6. 10/10/91 improved mounting of front bonnet grill to address warpage 7. 10/10/91 front suspension shocks and springsproduction improvement 8. 06/01/92 rear A-arm fix point height reductionproduction improvement 9. 06/01/92 Delco Alternator changed to Nipponproduction improvement 10. 08/18/92 door grillsimproved strength 11. 08/24/92 oil sump tank ground strapimproved gauge operation 12. 11/03/92 front timing bearingreduced noise 13. 08/18/93 harmonic balancer replacementreduced weight - added 2hp 14. 08/20/93 clutch thrust bearing/slaveproduction improvement Other factory enhancements: the change in final drive ratio The 1994 348 Spiders have a 4.34 to 1 final drive ratio. The 1993 348 TS's have a final drive ratio of 3.53 to 1 The 1992 & 1993 Ferrari 348 tb and ts Serie Speciale had their rear track widened by 50mm from 1578mm to 1628mm by adding 25mm of offset to each wheel, and their final drive was shortened from 26/27 on the earlier cars to 25/29 on the SS. A taller fifth gear was fitted (early cars having p/n 70000592), to maintain top speed with the new lower main gear installed. The 1990 348 TB's have a final drive ratio of 3.56 to 1. the stainless steel fuel line change, the major change to the Spider one-can exhaust from the old 2-can muffler, rear subframe upgrade to part number 4628, the change from the Motronic 2.5 to Motronic 2.7 ECUs (at and above chassis #86406), the increase in redline to 7800 RPMs (Spider, SS, Challenge, Competizione), the battery location switch from the rear bonnet to beneath the front bonnet (1992), larger intake plenums (for GTS, GTB, Competizione), 50mm wider track via 25mm wheel offsets, exhaust cam pulley setting re-indexed (U.S. Challenge 348's and Euro GTB, GTS, and Spiders), and the front bonnet A/C fuse switch from blade to inline bullet. 1989 model Ferrari 348's did not have the mad mouse seat belts. Early 1989 models had an external radio antenna. 1992 models and up came with body colored side skirts and spoilers. SS models had a reverse curve front spoiler (and small lip), removed rear grill, kevlar seats, chrome prancing horse "cavallino" emblems front and rear, strengthened door panels, leather interior door panels, and a taller 5th gear. Challenge models also came with aluminum pedals, an alternate fuel pump, a lighter front bumper, roll cage mounts, carbon fiber brake cooling ducts, a bigger heat shield, rubberized tow hooks front and rear, exhaust timing advanced, and 18 inch speedline racing wheels (225/40 ZR 18 front and 265/40 ZR 18 rear). Competizione models came with carbon fiber bumpers, aluminum and carbon fiber "thin" front bonnet and rear decklid, carbon fiber undertray, F40 half-shafts, upgraded fuel mapping in the ECU chips, lexan rear window, 15 inch brakes, and a strengthened frame.
