TnA Ultra Duty "Clamshell" Engine Mount Replacments - pre '88 ('91)

[CFMi]

Hey Guys!!

I've been making these for a couple years now, and for some reason never really pushed them. I figured now that I have a decent supply of bushings at my disposal and the means to make these pretty quickly, I'd post them up here They are 1/4" plate steel, and use a 9/16" crossbolt (compared to the factory 1/2" bolt). Good quality polyurethane bushings are included, and to save cost and shipping weight, there will not be any fasteners included, other than the 9/16" ones of course.

Comparison to factory:

Included in the kit:

Pricing is $95 plus shipping for the set. PM me to order for now, until I can get them up on the website.

Thanks for checking them out!

-Darren

 

[Deuling]

Will the other plate with the little torque rods that mount to the inspection cover still fit behind that? Just making sure.

 

[CFMi]

Will the other plate with the little torque rods that mount to the inspection cover still fit behind that? Just making sure.

Well, these should fit as a replacement for ANY GM clamshell style motor mount (pre 1988 trucks, pre 1991 SUV's). When I designed them, I had three sets of the factory ones that I measured and basically took an average of the three for spacing purposes. I am not aware of any clamshell style mount that was ever made differently and still looked like these. So if you had the little plates with the strut bars to the trans, as long as the motor mounts were the clamshell style, these should work!
*NOTE: If anyone has any information that there were different height clamshell mounts, please let me know as I don't want to false advertise these. As far as I've ever seen they are all the same. (as long as they look like the ones in the picture!)

-Darren

 

[63chevyll]

I would specify 73-87 trucks and K5s and burbs up to 91.

The 88+ trucks have a slightly different clamshell. Looks good to me.
Now....thinking ahead a bit. If the engine side would bolt directly to a LS engine. Could be used for the conversion stuff

 

[CFMi]

I would specify 73-87 trucks and K5s and burbs up to 91.

The 88+ trucks have a slightly different clamshell. Looks good to me.
Now....thinking ahead a bit. If the engine side would bolt directly to a LS engine. Could be used for the conversion stuff

You are correct, the late model mounts had a "step" built in to them and aren't flat on the bottom. They don't really look like these, but they really are still a "clamshell" style design. I should probably distinguish between them. I wonder what the car stuff looked like in later years. Hmmm.... More to think about.

I would love to build a set of these with LS mounting holes for a direct bolt-in, but alas, I have no LS motor and no money to put towards one at the moment. If there is anyone that wants to bring their truck and LS swap to me in Greeley, CO - I'll build you the first set for free

-Darren

 

[63chevyll]

As far as the car ones....
I'm not sure. The caprice, and metric chassis had a few different styles

 

[muddysub]

a set of these to mount a 5.3L would be SWEET, someone get this man a 5.3L!!

 

[CFMi]

a set of these to mount a 5.3L would be SWEET, someone get this man a 5.3L!!

I completely endorse and agree with this statement!!!!

-Darren

 

[POORBOYK5]

After multiple changes of clamshells with a friend of mine on his BBC swap into a 86 K5. Only thing we've noticed that is of any real relevance is carb'd BBC. Some carb'd BBC's use a tall mechanical fuel pump. These require the engine to sit a little higher than your avg clamshell. With the common one on the engine, it allows the fuel lines from the fuel pump to contact the factory engine crossmember. This can be corrected by using a high performance or marine mechanical fuel pump. End result? I think your mounts will work for everyone. They may have to use a different fuel pump on BBC's

 

[Heavyleft]

I hit up Darren about these motor mounts late last week and these showed up this week. Plan to get them installed this weekend barring weather holds out.

 

[diesel4me]

I was under the impression 4x4 mounts were different--the distance between the engine pad and the thru bolt mounting hole was 1" or so further away on the 4x4 trucks I swapped engines in--when I tried using the "car" clamshells that came on the other engine,it tilted downward at the front, and the oil pan and balancer were almost touching the crossmember--had to swap the original clamshells off the truck engine to the one being swapped in,to get it "level" and have sufficient crossmember clearance ...