LSx swap trans question

[tx1]

I'm currently in the process of installing an LSx into my syclone and have a few questions. I have the engine bolted up to a 4l80e with an RPM trans crossmember. I took my angle finder to the tailshaft of the trans and found that it is -6 degrees (pointing downwards). The differential is right at 0 degrees. Do you guys think that the trans pointing down like that is too extreme of an angle or do you all think it is ok to proceed and try to find a wedge for the rear end?

The transmission is already close to hitting the floorpan so there is no room to space it up any or something of that sort. I did a search and really didn't come up with anything so i'm having to ask you guys. Any input in the right direction is greatly appreciated.

 

[Norm]

Re: LSx swap trans question

Did you "clearance" your tunnel? What did you use for engine mounts and a oil pan? Is your engine as low as you can get it ? Is that measured with a load in the vehicle?

 

[tx1]

Re: LSx swap trans question

The tunnel clears the transmission all around.

I do have the engine sitting as low as possible with mounts that I had to end up making. The oil pan is a 2007 truck pan that I cut in order to make it fit. As the engine sits right now with the oil pan on and trans bolted up, everything clears. Not a whole lot but everything does clear the trans tunnel, frame, differential, etc.
The specs I gave are with the truck sitting level on the ground.

I might be forgetting to add something else but that's where I'm at with the truck as of now.

Thanks

 

[Norm]

Re: LSx swap trans question

On my Ty I had to "enhance"tunnel. I folded the lip (firewall/floor) smooth and it needed some room where the trans coooler fittings are. Who's mounts are you using? What exhaust manifolds are you planning on using? Sounds like you need to come down on the engine mounts or up on the transmounts, or a combination of the two. You might have to put in a pinion angle shim for the rear end leafs, but you shouldn 't have to unless your leafs are a lowered set.

 

[tx1]

Re: LSx swap trans question

The truck previously had the rpm v6 mounts welded in so I cut those off and made my own mounts to position the engine where i wanted it. I will be the one fabricating a set of up and forward headers for it, that way I know for sure everything will clear for this particular truck without hassling with other headers that "might" fit. It'll be cheaper as well.

The oil pan clears the differential by about 3/16" so there is no way I can lower the engine. I had to offset it to the passenger side a little bit as well that way the oil pan bolts don't hit the front diff (it's that close). Offsetting it will also give the driver side most rear primary tube more clearance that way it doesn't hit the steering shaft. The tightest spot clearance wise for the transmission is about maybe 1/4" or maybe a little tighter so I don't think there is no way I can lift the trans up unless I make drastic changes to the trasmission tunnel.

I do have the lowering springs on my truck but they don't have a wedge. I've located a few wedge kits from other companies, just doing my research before I make unnecessary purchases.

By chance did you measure the angle of the transmission tailshaft and rear end when you did your swap? It seems like my only solution is having to put a wedge under the leaf spring but I am just wanting to make sure that the tailshaft angle on my truck of -6 degrees (pointing down) isn't too extreme of an angle.

Thanks for the quick replies.

 

[Norm]

Re: LSx swap trans question

My tail shaft was 4* when it was finished. I had Bell lowered leafs on it and ended up putting stock dearched ones back in it.

 

[tx1]

Re: LSx swap trans question

Hm, I'm in the ballpark of your specs it seems. I might just go ahead and proceed with it and order the correct wedge plate for the rear end. Thanks alot for the help.

If anybody else has anything they might want to add, please feel free.