The bolt pattern depends on the bellhousing size. The big bell takes the 11.5 bolt pattern and the small bell takes the 10.5 pattern. I have a 164t 50oz 11.5 bolt pattern I would sell for real cheap since I went with a 157t 50oz 10.5 flexplate
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88LX 5.0,C4,BBK LT's, Race magnum bullets, K&N, ASP 3" Crank pulley, 3.73's, ram air, air bag, skinnies, battery in the hatch, 75hp NOS Dry Kit, Explorer intake
8.10@84 N/A 1/8th T-5
7.61@89 N2O 1/8th T-5
http://www.angelfire.com/ns/PurgingPony/50mainpage.html