converter bolt pattern

Ok I went to the local speed shop to get the flywheel and i ran into a problem. The guy across the counter ask me what size the bolt pattern was on the converter for c4 trans and I don't know. I have not yet removed the 250 from the car so I can't measure it. So can anyone help me with the bolt pattern measurement for a stock c4 converter I think I need a 50 oz and 157 tooth and 10.5 bolt pattern.

 

I just purchased a flexplate for mine. The engine being an '85, it required a 50 oz. Yours, I believe requires a 28 oz. I still have the 28 oz if you're interested?

 

No my engine is a 88 ho 5.0 roller motor

 

That's the one I purchased from Jegs (50oz/157 T/10.5) for my 85.

 

what is the part number and what is the cost

 

My mistake; I've ordered so many parts in the past few months, I thought it was from Jegs; Got it off ebay for $32.00