350 going in GMC

[Andyboy]

Ok I've looked and can't find info. I read about 67-72 perches going in 60-66 chevy trucks, and theirs holes on the frame and crossmember where you can bolt the perches to. But on my GMC there is NO holes, so where is the placement for the GMC's? This is a first for me, so any info would be great.
Thanks

[Captainfab]

The '67-'72 small block motor mount brackets will move the engine forward from the original location in the '63-'66 trucks. You can also use the motor mount brackets for the '63-'66 Chevy's with the 230/250, 283 or 327. These are also the same as the '67-'72 230/250 brackets. These will locate the engine in the original location. As for finding the location, there should be 2 holes on each side of the front suspension crossmember. The front holes will be for the '67-'72 small block mounts, and the rear for the '63-'66 mounts. You may need to set the engine in place with the trans bolted up to get the exact location for the holes on the top of the frame.

[Andyboy]

My 62 gmc has no holes on the front crossmember. Is there an easier way?

[padresag]

there is quite a bit of info in the FAQ section above
http://67-72chevytrucks.com/vboard/s...d.php?t=369663
ron

[Andyboy]

Yes there is alot of great info, but I was looking for where to sit the motor mounts on the frame. A measurement, maybe from the front of the frame horn to drill the holes for the mounts. Never installed an engine before, but I know I can do it. Just hoping there was a little more to go off of. Thanks

[padresag]

Originally Posted by Andyboy

Yes there is alot of great info, but I was looking for where to sit the motor mounts on the frame. A measurement, maybe from the front of the frame horn to drill the holes for the mounts. Never installed an engine before, but I know I can do it. Just hoping there was a little more to go off of. Thanks

what trans are you going to use?
ron

[markeb01]

As best I can determine and as shown in the photos, the center of the front motor mount bolt is 7 3/8” back from the center of the large hole in the top of the frame. The dimension doesn’t show clearly in the photo because I couldn’t line up clearly directly over the bolt, but that’s what it is with eyeball vision:



The passenger side is 7 ¾” back from the center of the same large hole. The first shows the orientation and the 2nd photo clearly shows the measurement:





Bear in mind I never measured to arrive at these dimensions back when the engine was installed. The motor mount location was dictated by where the engine ended up after the transmission was bolted to the tailshaft crossmember. The transmission mount was assembled loosely to the rear crossmember, the rubber motor mounts were bolted to the engine, and the towers were bolted to the motor mounts. The engine was then lowered into place and marked where the towers lined up, as Captainfab described. Also note these dimensions apply to 67-72 frame towers on a 60-62 frame with a 1" spacer between the frame and the tower.

Are you planning to use a rear crossmember under the transmission or keep the original stick shift mounts on the bellhousing?

[Captainfab]

Sorry about that. I did not realize that the '60-'62 GMC's did not have those holes until I checked when at the shop today.

If you are keeping the manual trans and original crossmember mounted bellhousing, that will determine the location for the motor mount brackets. If that is the case, I would just set the engine in temporarily with the motor mounst loose. That way you can adjust them to be the same on both sides. Then mark the hole locations and then remove the engine and drill the holes.

If you are converting to an auto trans or a manual trans with a rear mount, the dimensions that markeb01 gave, will work.

Originally Posted by Andyboy

My 62 gmc has no holes on the front crossmember. Is there an easier way?

[Andyboy]

Thanks guys I can picture it. You guys are awesome.
Posted via Mobile Device

[Andyboy]

Here are the pics. It has a 700r4