1981 911 targa engine/transmission support

[jessieherrera]

If you can help me or find the answer it would be greatly appreciated. I have a 1981 911 Targa. The engine and transmission are supported by a cross-member which is bolted by 4 large bolts to the body/frame. 2 in the back, 2 in the front. The 2 forward most threaded holes on the aluminum body/frame that the cross-member bolts in to have been severely damaged and will not support the engine/transmission securely/safely. The holes are too large to repair so they need to be welded. I need to identify what type or series of aluminum/material it is (Example: 6061 aluminum, 5052 aluminum, 1100 aluminum, etc.).The properties of the different aluminums vary immensely I desperately need this information to acquire the specific materials needed to weld it. This information is very critical. I’m restoring the car and I have invested a great deal of money in it. Your help would be greatly appreciated. Thank you.
Jessie Herrera

[303462]

Hi Jessie, that is steel. Weld and retap or drill & tap for time sert. Dave