I have driven several 90s GT1 championship seasons and achieved very good mixed up results with the following cars:
legion_nissan_r390
legion_toyota_ts020
legion_mercedes_clk_gtr
legion_mclaren_f1gtr_longtail
legion_lotus_gt1
legion_ferrari_f50gt
legion_porsche_911_gt1
f302_panoz_esperante_gtr1
rss_lmgt_toyama_2zero_v8
rss_lmgt_nisumo_r39_v8
jaguar_xj220c
Download the readme, you`ll find ballast and restrictor settings for the cars above there for V. 0.90
Note: The Jaguar is just a grid filler. Bad to drive and on most tracks much weaker compared to the rest of the field.
IMPORTANT: The results may and will vary from one track to another. Depending on track characteristics
If you know another cars which belongs to that category, give me a tip.
Any feedback is welcome !!! Have fun