68 T400 crossmember location

[budd01]

i have a 68 short box with a 396 and a T400 trans, the truck came with a I6 and a standard trans, then someone else installed the 396 using the I6 bellhousing and just welded up some motor stands, this placed the engine so far back i could not remove the distributor, i want to do it right, looking at the frame there are 7 holes where the crossmember bolts up, with the hole centers at about 3-3/4" on the crossmember that gives me 5 different locations it would bolt up, the motor stands i have are 73 but they look like they will fit and i'll be able to use the clam shell mounts, i'm hoping someone on here can tell me the proper location where the trans crossmember bolts and i'll work forward from there to find the location for the motor stands, i have shown 5 options, F is for the front of the truck and R is for the rear, ; thanks