Measure the bearing retainer on the trans you plan to use. The bellhousing center hole on the 55-67 is a little under 5" and the 68-72 is about 5 1/4". 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