What is the advantage of going from a 4spd manual to a 5spd manual? My csi cruises at about 3000rpm at 70mph.

For me to do a 5 speed manual transmission conversion from my 4 speed in a 73 3.0CSi do I need to get one of the following transmissions:

80” or 81” 528i, 635 or 735,
82” 528e, (the bellhousing won't fit, will use old 4spd housing,)
85” 535I,

82” & 85” 528e's and 85” 535,635 and 735's, as well as E30 M3's
need the shifter assembly and speedo drive from the 80-81 528i.

Should use a 80-81 Getrag 5 speed to get a speedometer drive.

I would also like to make the short through shifting conversion while I am at it. Is this possible and worth it?

Does any one have a list of what is required to do this conversion, or a how to description? Does any one have the part number or model number from the transmission so I can find one easy if it isn’t in a car? Please let me know. Let me know if you have a spare one as well that you could part with.

Troy

I hear that it drops your rpm about 800 at crusing. I dont think it can hurt unless your climbing a hill. I need to replace third gear in my 4speed so I thought I would just do the conversion. If it is too exspensive I will just stay with what I have.

Troy