Jahns pistons

I have a set of Jahans pistons for an old flat head that I need to identafy, dose anyone have a old Jahns piston book to tell me what they are?
Part numbers on box is as follows, 8 1105 H RP STD 2 1/64 Def 4 1/8.
Pistons are for a 4.125 bore.
Thank you for any help

 

First of all, welcome!

Second, you'll probably get more responses in the main General Discussion area.

Third, looks like they're probably for an Olds - http://www.jalopyjournal.com/forum/showthread.php?t=538903

 

Welcome from Indy.....Keep em' straight draider!

 

Welcome from Kansas.
That's cuz draider just made grenade inspector...AND he's from Texas!