Sad to see a real sprint bite the dust. You will need new springs as the 428 motor is much heavier than the OHC. You will need a new rad for more cooling but should just bolt up. An 11 inch clutch will fit a V8 bell housing but it's hard to remove the bellhousing in the tunnel with the 11 inch (from experience). 10.4" ought to work OK. Older Muncies were 10 spline so be sure you get the right clutch disc.