jago

hi all
i am in the process of getting a 78 911SC with a steel WB conversion.
this car does still sit on the original SC chassis.
PO has 18 x 8/9 with 1" fr and 2" rear spacers.
they are some kind of aftermarket not sure of make,
i have a bead on a set of RH speedline reps 18 x 8.5/10
please advise on proper spacers and tires for this setup
or if this doesnt make sense at all.
thanks in advance john