Mounting engine mount bracket with bolt vs stud

[sir911]

Hi folks!

Sorry for the basic question. I’m almost done rebuilding a 3.0 engine to swap into my ’76, and when I went to bolt on the engine mount bracket, I realized the crankcase is missing the four M10 studs that secure the bracket to the case. Since the original studs are no longer available, I’m planning to use class 10.9 bolts in the appropriate lengths (40, 45, and 50 mm), but I wanted to get your opinions on whether there’s any issue I might be overlooking.

Thanks

[faverymi]

Keep it original.

https://belmetric.com/studs-and-rods/

[JimmyT]

PET '74-'77 911, Fig. 1-01-05, #02 999.062.090.02 Stud, M10x40 Qty: 1 PCNA List 2026: NLA
PET '74-'77 911, Fig. 1-01-05, #02/1 999.062.039.02 Stud, M10x50 Qty: 1 SS: 99906218302 PCNA List 2026: $8.28

PET '74-'77 911, Fig. 1-01-10, #02 999.062.090.02 Stud, M10x40 Qty: 1 PCNA List 2026: NLA
PET '74-'77 911, Fig. 1-01-10, #03 999.061.056.02 Stud Qty: 1 PCNA List 2026: $3.17

For 999.062.090.02 try VW N90296401, ~$4.00

[Bill Verburg]

Originally Posted by sir911

Hi folks!

Sorry for the basic question. I’m almost done rebuilding a 3.0 engine to swap into my ’76, and when I went to bolt on the engine mount bracket, I realized the crankcase is missing the four M10 studs that secure the bracket to the case. Since the original studs are no longer available, I’m planning to use class 10.9 bolts in the appropriate lengths (40, 45, and 50 mm), but I wanted to get your opinions on whether there’s any issue I might be overlooking.

Thanks

Mechanically there is no difference

the studs make it easier to hang the mount on installation

[brighton911]

Just be very sure the bolt length provides adequate thread engagement and super important, without any chance of bottoming out.

[sir911]

Thanks folks. I went with bolts. I measured the depth of the stud holes (they are 25mm) and went with bolts long enough to go that deep.

Originally Posted by JimmyT

For 999.062.090.02 try VW N90296401, ~$4.00

Thanks Jimmy. This stud is also missing on my 2.7. I'll get the VW for that rebuild.

[PeteKz]

Using bolts instead of studs might make it easier to install and remove the engine mount and cross bar with the engine in the car.