'79 J-10 LS swap with Novak motor mounts

[Txflyer16]

I'd appreciate some wisdom/advice from someone who has done this before. I'm a newbie, have never hung a motor before, and I'm stuck on where to weld the brackets. The current placement I used came from a pic I found online. What else do I need to consider? It's an LQ4 (6.0) with a 4L80e with an Atlas 2 TC attached to GM 14 bolt rear and Dana 60 front axle.

X,Y,Z and U,V,W?? Should the motor be in the center of the frame rails and perfectly vertical? Should it be parallel to the frame? Should the engine sit level? I'd like to use the factory crossmember (with modification) but don't know how high the rear end of the transmission needs to be.

See attached pics. Please help. Thanks!

[Yeller]

You're going to get a wide variety of answers but having done a lot of swaps I'll give you best advice that I can.

Engine should be level side to side. Front to back varies and is hard to know for sure without the front clip on the vehicle. I'm always one for pushing the engine, transmission, and transfer case as high as possible, but the intake has to clear the hood. On a FSJ you can probably get away with setting the transfer case 1/2-3/4" above the bottom of the frame then set the engine at a 2-3 degree rearward slope toward the back of the truck.

Generally, I will push the motor, transmission and transfer case slightly to offset away from the front differentia by 1 to 1-1/2" to provide clearance for the front differential. You do have to be cognizant of the location of the steering column, brake booster and other items when doing that, they must still fit. My truck for instance I used a Trail Blazer manifold on the drives side, it is 1-1/2" closer to the engine block than the typical LQ4 truck manifold. It is close enough the ear of the bell housing has to be cut off to clear the manifold.

Lastly, I wouldn't weld anything beyond what you are happy to cut apart until the front clip is on and everything can be confirmed to fit. Hood, radiator, steering column all engine accessories, everything is a factor and needs to be accounted for.

[Txflyer16]

Thanks Yeller!

[thej10guy]

I have a 5.3 4l60e in my truck. I did not use the novak motor mounts, I just used universal ones because they were way cheaper. I don’t have exact measurements of where I mounted the motor. It isn’t perfectly level front to back, it is tilted slightly down in the back I am pretty sure. I used the original tranny cross member, I just moved it back, cut a slot in it for the front driveshaft and raised the section where the tranny bolts to it by 3/4”.


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[thej10guy]

This is what I did to the crossmember to get the transmission pointed where we wanted it. With where we placed the engine, we were able to reuse the OEM silverado driveshaft that we had without modification of the driveshaft at all (other than changing u joints).


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[Yeller]

J10Guy and I did our crossmembers similar. I used a 4L80E like you and needed more length and just moving the crossmember back was a lot more work, I just made a spacer/adapter to reach the mount. I used the same mount as he did, and in reality probably is offset about the same amount that the 4L80e is longer than his 4L60e.

FYI I may have pics of this in my build thread that I do not have available in my files, a link to that is in my signature.

[Txflyer16]

J10Guy and I did our crossmembers similar. I used a 4L80E like you and needed more length and just moving the crossmember back was a lot more work, I just made a spacer/adapter to reach the mount. I used the same mount as he did, and in reality probably is offset about the same amount that the 4L80e is longer than his 4L60e.


I don’t have a pic yet, but I put the crossmember in the aft set of holes and just extended it to the rear with a 2” piece of angle iron. That will put the OEM transmission mount essentially level with the top of the crossmember.

Should the tail of the tranny be higher than that? I plan on running 37” tires on ton axles, so I’m guessing 8-9” of lift??

[Glad the Impaler]

This is what I did to the crossmember to get the transmission pointed where we wanted it. With where we placed the engine, we were able to reuse the OEM silverado driveshaft that we had without modification of the driveshaft at all (other than changing u joints).


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I was able to space my NV4500 up 3/4" just like this to get my engine angle and t-case angle gravy. I used a different motor mount set - the advanced adapters universal Gen3 LS wide frame mounts.

Here are the best example photos I could find. My main pinch points were firewall for stock truck intake and passenger side headers to factory heater core box. I did new suspension and axles so I had some other stuff I was working around / had freedom from as well. I went MANual transmission as well - so slight difference in fit.

[Yeller]

I don’t have a pic yet, but I put the crossmember in the aft set of holes and just extended it to the rear with a 2” piece of angle iron. That will put the OEM transmission mount essentially level with the top of the crossmember.

Should the tail of the tranny be higher than that? I plan on running 37” tires on ton axles, so I’m guessing 8-9” of lift??

You will want the lowest part of the transfer case to be 1/2-3/4" higher than the bottom of the frame, whatever it takes to make that happen.

as for lift amount it completely depends on how much sheet metal you are willing to trim. I currently could run 35's with 2-1/2" of lift with minor trimming, currently running 33's so no trimming required, even when it was stock. keep in mind, the lower the lift the better it will drive, the better it drives, the better it works in the dirt. Poor road manners are still present in the dirt, it just masks them. Those poor manners do limit performance in every aspect whether in the dirt or on the road. 37's fit stock if you're willing to trim enough

If you wheel it, low lift will drive circles around the tall trucks unless you're into mud pits, then yes you need more clearance.

[Txflyer16]

I'm trying not to trim any...I'd like to keep the fender flares intact. How much lift will that take?