Motor Mount Perches?

[RustyPile]

Originally Posted by 57taskforce

Wrong. not for K trucks. The picture I posted above is from my 72 K20 which is identical to his most recent post.

I stand corrected.. I was thinking both the C and K received the new "safer" mount that wouldn't separate.. I know that the 1971 big block had a 2 piece front mount similar to the rear mount.

[57taskforce]

No worries, it’s easy to do. K trucks can be a bit of a pain to keep up with as far as changes year over year. They didn’t get some of the changes that the C’s did as things went on.

[RustyPile]

Originally Posted by 57taskforce

No worries, it’s easy to do. K trucks can be a bit of a pain to keep up with as far as changes year over year. They didn’t get some of the changes that the C’s did as things went on.

In those years, I was a GM dealership mechanic.. What I remember most was all the cars and trucks that came in with broken motor mounts.. Around '69 or '70, Chevrolet issued a TSB about broken mounts.. Later they issued a "full blown" recall.. The fix was to install a cable device that wrapped around the UCA shaft and bolted to an exhaust manifold bolt. What I also remember about the Ks was all the cracked frames around the steering box and motor mount brackets with holes worn through from the rubber getting soft and allowing the mount edge to rub against the bracket.. Some of this happened while the vehicle was still in warranty.. By 1975 - 76, I had advanced my skills and no longer had to deal with heavy line repairs..

[Orefactory4x4 swb]

Yeah, after looking at photos. I think you have right setup. May need to flip it 180?

[Orefactory4x4 swb]

This might seem stupid, but if you’re trying to slip it into place all bolted together I don’t think you can.
Something I am running into right know is I have mine in the factory holes on frame, but distributor switching it efi is right up tight. I’m thinking about drilling new holes and moving everything forward 1 inch.
Good luck on your build. I’ve struggled on a few things like you’re having. But it will come together. There’s some smart guys on this site about these trucks.

[Orefactory4x4 swb]

Yeah, after looking at photos. I think you have right setup. May need to flip it 180?

[68isgreat]

Originally Posted by Orefactory4x4 swb

Yeah, after looking at photos. I think you have right setup. May need to flip it 180?

Thanks! I've looked and couldn't find a simple explanation of what the K mounts look like and how the motor is supposed to attach to them. I have the crossmember just resting on the frame for photo purposes. I'll disassemble and make sure it's attached and oriented correctly when I get ready to drop in the engine.

[68isgreat]

Originally Posted by RustyPile

In those years, I was a GM dealership mechanic.. What I remember most was all the cars and trucks that came in with broken motor mounts.. Around '69 or '70, Chevrolet issued a TSB about broken mounts.. Later they issued a "full blown" recall.. The fix was to install a cable device that wrapped around the UCA shaft and bolted to an exhaust manifold bolt. What I also remember about the Ks was all the cracked frames around the steering box and motor mount brackets with holes worn through from the rubber getting soft and allowing the mount edge to rub against the bracket.. Some of this happened while the vehicle was still in warranty.. By 1975 - 76, I had advanced my skills and no longer had to deal with heavy line repairs..

Wow, you are the guy to talk to. Thank you for posting.

[68isgreat]

Originally Posted by 57taskforce

The upper part of the crossmember goes under the top of the frame rail. From there the engine rubber mount bolts to the crossmember via the big holes at the tops of the upper brackets in the crossmember if that makes sense. See my old picture above for mounting on the crossmember to the frame.

In the picture in post 14 you can see where the rubber mount was rubbing on the upper crossmember brackets below the big hole. The mount just lays on the crossmember and bolts into place. I believe they were 7/16 bolts and washers if I remember right. It’s been a few years since I replaced all that on my truck.

Edit*** All you are seeing in this picture referenced earlier in this thread and reposted here is the disposable rubber mount still bolted to the crossmember and unbolted from the engine. That’s the same mount you can buy at NAPA, orielly, autozone… whatever your auto parts poison is. I think you are overthinking the setup a little bit.

I definitely was! Thank you very much.

[Orefactory4x4 swb]

Here’s some pics of mine. It was a truck needing a lot of work, but I’ve done it all from top to bottom. From metal work lift paint wiring and on. Myself on it all.
Can’t wait to fire it up soon.

[Orefactory4x4 swb]

You can zoom in on the mounts

[68isgreat]

Originally Posted by Orefactory4x4 swb

You can zoom in on the mounts

Awesome, thanks! Can't wait to get my motor and trans installed. New crate 350 tbi with rebuilt 700r4 and passenger drop 241c. Waiting for this rain to stop in Oregon. Ugh!

[57taskforce]

I was thinking about this a little more. These pictures are how I repaired the frame on my SWB K10. I would check your frame really good for wallered out engine and crossmember mount holes, it’s super common on the K trucks. I would also check the area around where the steering box mounts for cracks before you install the engine. That’s another Another super common thing on the K trucks, that’s much easier to repair when the engine and front body clip are out of the way.

Someone at some point in time removed the very front frame crossmember and ran the trucks that way with 33” tires for who knows how long. The frame was cracked pretty bad at the steering box, as well as the upper holes were elongated on the frame and motor mount crossmember both. I drilled the holes to exactly 7/16” and then welded these thick washers to the frame. The washers were originally 3/8” that I drilled to 7/16” in an effort make sure the fit was as tight as possible to try and prevent any excess movement of the frame rails while driving. I had to do similar to my K20 at the very front crossmember as the rivets were all loose on it as well. My K10 is a long term project that I had to boot outside for a while so excuse the surface rust on the frame where it was repaired. I’ll get back on it one of these days.

[Orefactory4x4 swb]

Hey I got a question for you 57 task force
My efi is right up against the firewall with top on.
Would it start grounding out wires in the back? Can I just run it like this or pull it all forward one inch. I do know it will be a pain in my a**, but now would be the time as is all opened up still.

[57taskforce]

Honestly I don’t think I would worry too much about it as long as the wires are properly protected with quality loom and routed in a way that they won’t be pinched. Distributor clearance is definitely tight with the engine in the rear position (factory 4x4 V8 position) but it’s not something that can’t be overcome. If an HEI will fit (and it does) you should be able to clear everything needed for fuel injection in my opinion.

[Orefactory4x4 swb]

I’ll just run with it and carry on… thanks

[68isgreat]

Originally Posted by 57taskforce

I was thinking about this a little more. These pictures are how I repaired the frame on my SWB K10. I would check your frame really good for wallered out engine and crossmember mount holes, it’s super common on the K trucks. I would also check the area around where the steering box mounts for cracks before you install the engine. That’s another Another super common thing on the K trucks, that’s much easier to repair when the engine and front body clip are out of the way.

Someone at some point in time removed the very front frame crossmember and ran the trucks that way with 33” tires for who knows how long. The frame was cracked pretty bad at the steering box, as well as the upper holes were elongated on the frame and motor mount crossmember both. I drilled the holes to exactly 7/16” and then welded these thick washers to the frame. The washers were originally 3/8” that I drilled to 7/16” in an effort make sure the fit was as tight as possible to try and prevent any excess movement of the frame rails while driving. I had to do similar to my K20 at the very front crossmember as the rivets were all loose on it as well. My K10 is a long term project that I had to boot outside for a while so excuse the surface rust on the frame where it was repaired. I’ll get back on it one of these days.

Great suggestions, thanks. I suspect I may have to re-drill my engine and trans crossmember holes when I install the engine. Since I'm running a rebuilt 700r4/241C passenger drop from a 1990 Suburban, I bought a 1990 burb front and rear driveshaft at a wrecking yard, and my plan is to drop in the engine and trans and hook up the front driveshaft and use that as my guide as to how far forward to mount the engine. That way I'll only have to have my rear driveshaft cut to length. I don't foresee any issues with that approach unless the front driveshaft is a way different length than earlier ones, which I doubt is the case. If I'm wrong, I hope someone can chime in.

Someone also previously installed power steering on it, and they welded in a thick metal plate to reinforce the steering box area, and they welded up a crack also, so no worries there. I bought a new 1978 quick ratio ps box to replace the earlier one they installed though, which was 4.5 turns of the wheel compared to the newer 3.5.

I'm going to start a new thread in the k10 builds forum once I get some pics taken.

Thanks-

[57taskforce]

Here’s a dirty little secret. A lot of The square body front drive shaft should be around 29 1/2” at its operating length… want to take a guess at what at least the 69-72 K truck runs??? It should be 29 1/2”…. You very well may be able to bolt it right up in the original K position. GM changed the length of the transfer case to transmission adaptors to maintain the same overall lengths between the different transmission/transfer case combos for the 67-87 trucks. The rear driveshaft will be different because the square body trucks had a longer wheel base than the 67-72’s. You have a fairly rare combo there that I’m not completely familiar with. That was a 1 to two year combo but I bet the measurements are still very close to 67-72.

[68isgreat]

Originally Posted by 57taskforce

Here’s a dirty little secret. A lot of The square body front drive shaft should be around 29 1/2” at its operating length… want to take a guess at what at least the 69-72 K truck runs??? It should be 29 1/2”…. You very well may be able to bolt it right up in the original K position. GM changed the length of the transfer case to transmission adaptors to maintain the same overall lengths between the different transmission/transfer case combos for the 67-87 trucks. The rear driveshaft will be different because the square body trucks had a longer wheel base than the 67-72’s. You have a fairly rare combo there that I’m not completely familiar with. That was a 1 to two year combo but I bet the measurements are still very close to 67-72.

That's great to hear, thanks! I got the suburban rear driveshaft because I figured it would be long and I could have it cut it down to the exact length I needed. I went the tbi route because I was able to afford a new crate motor that way and still have fuel injection and overdrive. A new crate LS swap was out of my reach, and I didn't want to buy a used one. My truck will basically be an early 90's computerized OBS truck with a 68 body. Works for me!