On truck bellhousings the top holes are threaded in the bellhousing. The lower bolts are installed from inside the belhousing into the threads in the transmission. If you are installing a car transmission you just need longer bolts with nuts for the 2 lower mount holes.
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