Engine Mount BRACKET SET: : 58-64 V8This is the V8 Engine mount BRACKET set .. LH & RH. Your engine mount slips over this & the bolt goes thought it. Bracket head size is 2 5 8" not the smaller 2 3 8".. most 58 64's used 2. 5 8" Sold in pairs only This is whats also needed if changing from a 58 59 6cyl factory in line 6 to the chevy small block.. otherwise the tilt of the SBC will cause a rumble in the tail shaft drive line thats annoying.