Various torque specs for engine mounts and associated brackets
 

I need to know the correct original factory torque specs for the motor mounts and their brackets, etc. (1967 GTO).

Especially need the mount to block torque for those special castle head style bolts...plus the torque for the long through bolts attaching engine to the mounts.

I already installed the engine mount brackets to the frame but didn't know the specific torque required for those...I just guessed at 35 foot pounds.

Also, were there any washers between the castle bolts or just bolts alone? Inline Tube sells them with washers but I believe I bought my set from Paul Spotts. Both are after market but Paul says his are just like originals (no washers came with them)...so I assume no washers were installed from the factory?

Motor mount to block, 65-75 ft-lbs dry.

Motor mount through bolt 50 ft-lbs

I just found another spec that says 25-35 for both. I'll look some more.

Various service manuals seem to have different values. I use the ones in my first post.

FWIW, upon initial assembly on the line they were drawn tight with a calibrated impact wrench. They don't calibrate those wrenches after each use, so they do change. The aforementioned bolts aren't considered critical fasteners, and as long as they didn't work loose during their life cycle they were tight enough. The factory assembles most all these parts with automated machines, they aren't assembled by hand one by one. After 50 years wrenching for a living, I have never laid a torque wrench on any of the aforementioned bolts, same as the factory that originally built the cars, and engines never laid a torque wrench on them when new, I've never had one fall out, or break.

If your concern is loosening up then Loctite it, most all of the bolts have split lock washers on them anyway. if your worried about over tightening them then there are tables on the net that will give you torque values for bolts based on length, thread pitch and bolt materials tell you if the torque values are lubricated, or dry.

I realize there are printed torque values for most every part on a car, but in the grand scheme of things these bolts were never torqued with a wrench when assembled, and if taken apart in the field, don't get torqued upon re-assembly.

Your search gives different values in printed form, so which do you believe? As long as you're not stretching the bolt too far, and it doesn't loosen up, you're going to be fine.

What grade, diameter and thread-pitch are the fasteners?

I'd hope that Grade 5, 3/8-16 bolts aren't getting "torqued" to 65--75 ft/lbs.

I'd hope that Grade 8, 7/16-14 bolts aren't getting torqued to 25--35 ft/lbs.

Can someone possibly check their stock mounts to see if the bolts are un-washered? Will also ask in the Tempest/GTO section. Street is probably too generic and performance oriented. Thanks to all who responded!

Robert