302 to 351w swap with C4, now terrible noise
swapped out a 302 out of a 73 mustang for a 351windsor (1978). C4 transmission was left in place and worked well prior. Obtained new flexplate (pioneer fra-203). It was same diameter and teeth number as the previous flexplate on the 302.
Car seemed to run and sound fine upon starting. After driving at low speeds noticed some difficulties shifting into drive or reverse (the shifter moved freely but seemed to not drop into gear every time) as well as a faint scraping noise. The noise was consistent w scraping of torque convertor based on some youtube videos. Attempted heavier acceleration which yielded a terrible scraping/ fan belt slipping sound from the transmission.
I properly torqued and apples loctite to flexplate and convertor bolts and they were still tight at disassemble. The converter was seated properly on shaft at assembly.
I noted scrape marks on spacer plate and also that the flexplate was approximately 3/16 in thinner that the old flexplate.
I am not sure how to go forward and if it was the flexplate being thinner and which I should get. I have included photos. Any advice would be appreciated