Rebuilt transmissions needed?

Hey guys I have been rebuilding e30 transmissions and selling them to my fellow racers in the Spec E30 series. We do a very nice job with them and its been going very well. I have been thinking about branching out and doing some Z-car transmissions as well. We have done them in the past. Do you guys do them yourselves or just put in a used one or what? Pricing has been very reasonbale so far with a core turned in. I have several 4 speeds here and they are not doing much but collecting dust. any thoughts?

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