what year 210 5speed would work for 1200?

79-82 210 (B310) is probably the best one to use, as it will fit with out needing to midify the trans tunnel. and the input shaft is splined the same as the
1200 4 speed

I have found that, while the input shaft on the B-210 and B-310 tranny may be the same, the output shaft is different. What I have done is use a B-210 driveshaft and rear
axle. This also give marginally larger rear brakes and a larger (stronger?) ring gear.

I forgot to mention that I had problems with the transmission mounts (the sheet metal on the unibody) interfering with the speedo gear on the left hand side and one of the
sensors on the right hand side of the tranny. The automatic transmission cars had the mounts farther back than the 4-speed cars so there isn't an interference problem there.