Riddle me this...

Anyone know off hand what size allen head bolt is used to bolt the crossbar to the engine on a 1970? I lost one when I put solid engine mounts on the cross bar, and now it rattles under hard load thats how I fingered out it was missing. I'm going to replace the solid mounts with the Weltmeister poly trany mounts, looks like they will work for the early style engine mounts. Anyone done this I'm thinking they might need to be trimmed to fit the round hole? Or should I do something else?
Thanx...
Neu

PET shows a 10 x 70 hex head bolt

http://www.icbm.org/erkson/personal/Porsch...914_USA_PET.pdf

look on pg 83 of 320 in engine group. part #12

Thanks for the reply, it looks like all the same parts in the drawing but mine doesn't have a hex head bolt its an allen head because its receded in the crossbar, but it should still be the same thread and length. Now I just need to find two, I'm going to replace the missing one and the one that is still in, just cause its been rattling a lot and could be a little stressed...
Neu