The Alpha 1 will bolt right up with no modifications to any previous trasom assembly and bellhousing. The Gen 2 Alpha is not compatible with older TA's or the Alpha 1 setup. My boat originally came with a R drive setup. I blew it up with running nitrous and bought a new Alpha 1 in 92 to replace it. There is no modifications needed. Let me know if you have any questions I can help out.