Issues with LS swap and motor mounts

[downbytheriver]

Yesterday I installed ECE mounts and the 5.3, and I'm having issues with the oil pan hitting the rear section of the crossmember. I used the top outer two holes on each side, and drilled two holes in the crossmember.

I see a bunch of other builds that have ECE mounts being used with no issues. Does the mounting of these look right? It seems like the engine needs to be moved back a little.

[tinydb84]

Can you flip the mounts?

[C10_ustacould]

Does the 5.3L still have the truck pan?

[downbytheriver]

I COMPLETELY forgot to mention I had an fbody pan, sorry.

[C10_ustacould]

F-body pan won't work with ECE mounts. 2007 CTS-V will fit and is shorter than the truck pan.

[downbytheriver]

Damn damn damn.

I was thinking about putting some kind of spacer in there, but I'd like to avoid that.

Is there a known specific mount that'll work with the fbody pan and the 73-87 style towers? If I could just ditch the mounts themselves and keep the towers, I'd be set.

[downbytheriver]

Looking at the Dirty Dingo mounts, the site says they won't work with a low mount compressor, which is an issue with those.

I may have to go the spacer route.

[tinydb84]

Originally Posted by downbytheriver

Looking at the Dirty Dingo mounts, the site says they won't work with a low mount compressor, which is an issue with those.

I may have to go the spacer route.

You can move the compressor up or you can heat up the frame and bend it. They did it on an episode of Trucks.

How much space do you need?

[Hart_Rod]

I would sell the Fbody pan and get the CTsV pan. That way you will not have to hassle with moving the a/c.....

[Clyde65]

I would agree with^^^^

[68GMCCustom]

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[BR3W CITY]

If you do need to tweak the frame, its really not as big of a deal as it sounds. On my 66 there is the "factory bend" in the frame where it bumps out for clearance. I just mimicked that when I wanted extra clearance for the pump/lines on my powersteering/hydroboost setup.

[Robznob11]

You can probably get an inch or two by drilling new holes in the frame and crossmember and sliding the towers back thats what i had to do on my homemade mounts so the headers would clear the lower control arm.

[downbytheriver]

^^Rob, that's exactly what I'm going to do. I looked at it earlier, and figured I need a little under an inch backwards to account for vibration, etc. There's plenty of room under the hump for the tranny, but I think I'd have to go high hump with anything larger than this 4l60. The other plus of this is more potential room for ac condenser, radiator and intercooler.

I'd trade the pan out for the CTSV one and call it a day, but I already drilled a hole for the turbo drain in this pan.

The only downside I can see is that moving it might present an issue for the ac compressor. I'll have to take a look at it when I get the cab off. I'll post pictures when I'm done.

[smoky02]

I had this exact same problem. I did two things to fix
1. Heated the k member with a torch and beat the hell out of it
2. I installed spacers between the frame and the mount brackets.

[downbytheriver]

Okay, got it all tightened up and now it's great.

Moved the mounts back about an inch from the original holes I drilled, on both top and bottom of the motor mount. One bolt will definitely be close to the edge of the crossmember, but it'll hold well. The other good part about that if you use the ECE transmission crossmember, you won't have to drill any holes. It's a pretty clean install actually.

Bear in mind, this is all with a 4l60 transmission. Not really sure about the size of the sun shell on the 4l80.

Oil pan:


Auto trans crossmember: