my 1991 camaro originaly came with a 153 spline flexplate
when i put my new engine in should i use a 153 like it came with or a 168?

what is the difference

ps i am haveing my 700r4 rebuilt

 

153 and 168 are the number of teeth on the outside of the flexplate which mate with the starter drive gear (pinion). The 153 tooth is the "small" diameter (about 10.5 in.). The 168 tooth is the "large" (about 12.7 in) plate.

If the 153 tooth fits the torque converter, use it. It's lighter, and allows the starter to mount closer to the block for more header clearance. A standard GM 153 tooth flexplate weighs about 4.5 lbs.

A flex plate has a couple of functions:

1) It connects the crankshaft to the torque converter.

2) It flexes a little when/if the converter "balloons" or expands in use, hence the name.

3) It carries the ring gear (153 or 168 teeth) and puts it in a position where the starter can reach it.

 

Moving to "3rd Gen Tech".....

 

so it doesnt matter if i use a 153 or 168 it is my choice?

 

Do not get a 168, go her to find out why http://www.fbody.com/cgi-bin/3gen/read.cgi?msgid=21434