If you are going to do a SPI swap, check with Rod, AKA Racecougar and he can help. I got my 3.8 SPI from Greenleaf @ BlueRidge and 23rd St. for under $600. Now, if you run the SPI, you can get a TT kit from one of the MOOstang sites and go from there.
Welcome to the site.
Soon to have some MHS parts, cams, 'luminum block, lower compression, ported heads, autorotor, and need to make long tubes. I have almost all the stuff and need some #42-50s a bypass valve, and maybe a few other things.