bolts for motor mounts

[southwilrise87]

I finally got my engine dropped in and im that much closer to gettin my truck on the road but I only have one problem. I have the motor mounts resting on the frame mounts, but I still need the two single bolts that go up through the frame mount into the engine mount. Ive tried like two or three different sizes but none of them fit. What size is it? Is it course thread or fine?

[padresag]

what eng are you putting in and what came out
ron

[southwilrise87]

the PO had a 350 in it and Im putting in the 305 from my old camaro.

[padresag]

a couple of questions. there are 3 holes on the top of the frame where the frame perches go. are they mounted in the frt 2 holes or the rear? are you still using the 3 speed and is the rear eng mounting under the bell housing?
ron

[southwilrise87]

theyre in the rear holes. Im using the original 3 speed. Im not sure what you mean by the rear engine mounts. The mounts Im using are the 2 on the frame. The engine is in, I just need to know what size bolts connect the frame perch to the mount on the engine.

[MacAttack]

3/8-16 (course thread) x various lengths (depending on your access from below) , usually 2 to 2-1/2 inches long: GRADE 8 ONLY (bolts, nuts and washers).

[padresag]

Originally Posted by southwilrise87

theyre in the rear holes. Im using the original 3 speed. Im not sure what you mean by the rear engine mounts. The mounts Im using are the 2 on the frame. The engine is in, I just need to know what size bolts connect the frame perch to the mount on the engine.

rear eng mounts are the ones that bolt off of the bellhousing
the single bolt that connects the frame perch to the motor mount is a 7/16nc bolt.
there was a reason why I asked you those questions,but I guess that you already seem to know everything already, I will stop here.
ron

[padresag]

Originally Posted by MacAttack

3/8-16 (course thread) x various lengths (depending on your access from below) , usually 2 to 2-1/2 inches long: GRADE 8 ONLY (bolts, nuts and washers).

mac, that bolt is 7/16nc. there is no requirement at that position for a grade 8 bolt. a grade 5 bolt should have more shear strength than a rubber insulator( which is usually which fails)
ron

[damnyankee36]

Originally Posted by padresag

mac, that bolt is 7/16nc. there is no requirement at that position for a grade 8 bolt. a grade 5 bolt should have more shear strength than a rubber insulator( which is usually which fails)
ron

But, grade 8 is the correct grade as supplied from the factory although I agree, I think it's overkill. You would have a hard time getting enough torque on 7/16" bot to get the proper stretch.

In fact, I just discovered a couple days ago that one of my motor mount threads are stripped. Never saw it coming, never came close to tightening. The bolt threads, (grade 8) looks perfect.

[msgross]

did you use new "made in India" mounts? some of those suckers have metric holes or just plain crappy threads...

[southwilrise87]

i bought the mounts from napa, it said made in china on the box.....ya i know. the two previous sizes mentioned in the post both didnt fit right. i guess im going to have to guess and check what will fit and what wont

[padresag]

Originally Posted by southwilrise87

i bought the mounts from napa, it said made in china on the box.....ya i know. the two previous sizes mentioned in the post both didnt fit right. i guess im going to have to guess and check what will fit and what wont

there may be rubber in the holes from the vulcanizing process
ron

[southwilrise87]

thanks for everyones help. a 10mm metric bolt fit. put it in and tightened it up and pulled it back out to check. no damaged threads or metal shaving so i found the one. who woulda thought a metric bolt? thanks msgross for the suggestion