I'm buying a 68 Sprint. It currently has a 3-speed manual. I believe this is a Saginaw gear box. I want to install a Muncie 4-speed. I'm hoping the Muncie will slide right into the bellhousing, fork arm, clutch and flywheel. Is this the case? I realize a new throw out bearing may be necessary as well as warranted. The drive shaft may need altering or replacing too. Other than this, is this swap a bolt in? Thanks.