There are generally no bolt in parts for modified vehicles but you may get lucky. The driveshaft out of a 55-57 car and a 55-59 truck with a 3 speed is about 54" C/L to C/L. The 3 speed trans is about 22 1/2" which is close to the later 5 speed. You would need the fine spline front yoke to match your conversion trans. There should be some of these around that have been removed for upgrades and conversions.
Fred


1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes
1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes
2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans
1947 Willys CJ2A w/F-Head engine