the sik50s clutch is only the plates and springs were the other one is the whole clutch,Youd hav to ask one of the motor tech heads lol to see what diff is as,im a bit unsure, might just be bit easier to put the whole cluch in other then pulling stock one apart to put new plates and springs on??
And with the oil pump anything other than 88 id prob do it, and they recommend doing it as most dont just keep 88 limmos , they usually build up 108s ect..and they get a bit more $$$ of ya haha, but in the end is prob a cheep option to have done .if ya got ya motor apart all ready.
Gearing im running is 15-39? or 14 39?,