does a 260 need a weighted flexplate?

I'm changing out the engine of my Meteor with a 2 speed auto from a 221 to a 260. The original flexplated is balanced. Does the 260 require a weighted flexplate? Thanks much.

Ed

 

Put this on the main forum, it's a period engine and box, no one will complain any you'll get more hits.

 

221 , 260 , 289's, and 351C's all have the same 28oz imbalance [so do some 302's]

351windsors and late 302's [5.0 designation] went to a 50oz imbalance'
The easiest way to tell which imbalance the engine has is to check the firing order [providing the cam is stock]

All 221 / 260 / 289 /302 / 351C's had the 1-5-4-2-6-3-7-8 firing order.
whereas all 351w and HO 5.0 [302] had the 1-3-7-2-6-5-4-8 firing order.


Do yourself a favour and ditch the 2 speed "slush-o-matic" for a C4 [but you'll need to find a pre-66 5 bolt bellhousing]
A C4 will even wake up a 221 off the line

 

The 221 and 260 engines do not have the same (im)balance as the 289 etc.
From Bob Mannel, who wrote the book "Mustang and Ford Small Block V8", quoted from the Fairlane Club of America Technical Forum:

"The flex-plate for the 260 Fordomatic is counterbalanced 24.5 ounce-inches. The 289 requires 28.2 ounce-inches."

 

That flex-plate could be as difficult to locate as the five bolt C4 bel housing. I’ve been offered $400 for one that goes with a 64. 289.

 

I guess I need to part out my rusty '64!