flex plate confusion?

i have a 71 torino, with a c4 331 combo.

so i just got my brand new T.C.I torque converter. i am so close to putting the trans and motor back to one unit. but the flex plate is confusing me. i have a 11 inch torque converter, do i need to find a 11 inch torque converter fitting flex plate or just a standard 70/71 fitting one for c4 nothing special. i know there is teeth differences to, so does the teeth count matter? and will it mount up no problem or will the drilled holes have to be exact? also how do you have to balance them with the motor all buttoned up or can you take just the plate by its self? how much will it cost to? help will be greatly appreciated. 

dudeman 

the torque converter is a 11 inch 26 spline, and there are 157 teeth on old flex plate how would you find out it motor is 50oz, 28oz, or neutral balanced? the motor came from my brothers fox body, and it was a 5 speed, and the previous owner had it as a drag car mainly. i am going to look up how to find out but still help will be helpful.
dudeman

Motor year wont matter if it has been built by a shop. They usually reccomend a 28oz when doing any kind of stroker but it could still be a 50oz. You need to know for absolute certain what it is or you will destroy the motor. Try looking at the balancer and see if it is a factory unit? If its aftermarket take some pics and post them and try to get a part number on it. This will help a ton in figuring it out.

the flywheel is gone....it went when we sold the t5, but i will look at the harmonic balancer post pictures to will this correlate with the right flex plate oz if i look it up online? 

i really don't want to mess this motor up is there anyway to buy matching flex plate and harmonic balancer?

it you do get the wrong weight, the engine will shake considerably and you'll know it's wrong very quickly, you won't hurt it if you shut it off as soon as you realize it ain't right  

Edited by Rockatansky - 04-February-2012 at 7:32PM

Thats the factory 84 50oz part number and you would want to get a 50oz flywheel with the correct bolt patteren. The two Ford bolt patterns are 10 1/2" or the 11 7/16" sizes. You need to make sure which one you have and order accordingly. Mine is a Pioneer brand on my 347 in my Torino. Good luck and let us know if you need anything else.