Transmission Crossmember 5.3 / 4L60 Swap

[Prathbun]

I need some help.

I'm doing a 5.3 / 4L60 swap and I need some ideas for the transmission crossmember. I really don't want to use the OEM crossmember so I'm thinking about making my own. The OEM member is off by about 1".

Any suggestions or pics that you have would be greatly appreciated!!

[Prathbun]

Here are some pics of my crossmember

[Hart_Rod]

You could redrill the holes and use the facotory one. I used an ECE tranny crossmember.

[BP68]

I moved mine/redrilled holes for my 700R4 install.

But ECE and CPP make nice ones.

[ChevyFan24]

Did the ECE use the same bolt holes as OEM?

I have also used the original one and just redrilled.

[Shon]

hope to redrill my stocker this week!
I have not really looked yet, will the frame need redrilling or the mount location on the Xmember?

[Prathbun]

Thanks for the replies. I too am interested to find out if the ECE mount required redrilling. Seems that there are almost too many holes in the frame already.

[brad_man_72]

im drilling the frame to make my stock x member fit. i have other stuff to spend money on.
have you tried swapping sides with your motor mounts, they have about an inch of offset. it never hurts to move an engine back if you have clearance.

[Hart_Rod]

Originally Posted by Prathbun

Thanks for the replies. I too am interested to find out if the ECE mount required redrilling. Seems that there are almost too many holes in the frame already.

I used ECE motor mounts, ECE tranny crossmember and the factory 5.3/4L60E tranny mount (center bolt) and did not have to drill any holes.

[Puropedo]

Hart Rod, who makes those headers on your 5.3? Did you had any clearance problems? Do you mind telling us how much you paid for them? Thanks.

[brad_man_72]

doug thorley tri y 67-72 ls1 swap headers.... alot$. theirs a thread dedicated to those headers, i have a pair, very nice. could use a little more firewall clearance. and dont ever use "purple power" degreaser on them!

[Prathbun]

Thanks for the pics Rob!! If I had seen them earlier I would have used ECE stuff.

Currently I have Performance Online motor mounts and I wondering if the trans cross member that they offer will be a direct bolt up as well. Again, thanks for all the replies!!

[Hart_Rod]

Originally Posted by Puropedo

Hart Rod, who makes those headers on your 5.3? Did you had any clearance problems? Do you mind telling us how much you paid for them? Thanks.

They're Doug Thorley Headers. No clearance issues with ECE motor mounts. I helped them do some R&D so they took care of me, . You can check this thread out for more information and a board discount:

http://www.67-72chevytrucks.com/vboa...d.php?t=287231

Originally Posted by Prathbun

Thanks for the pics Rob!! If I had seen them earlier I would have used ECE stuff.

Currently I have Performance Online motor mounts and I wondering if the trans cross member that they offer will be a direct bolt up as well. Again, thanks for all the replies!!

I couldn't tell you if they will work with Performance Online mounts. I'm pretty sure there is no problems with the CPP mounts, but haven't verified that myself. If you have any more questions, let me know.

R/

[Puropedo]

Thanks brad man and hart rod for the info, hart rod, did u ended up using msd wires or the stockers? Also, do you need to use cats for this swap??

[brad_man_72]

no cats, just retune computer to use front 2 o2 sensors. and eliminate a bunch of other stuff while youre at it.
cant use egr with the DT headers.

[Hart_Rod]

Originally Posted by Puropedo

Thanks brad man and hart rod for the info, hart rod, did u ended up using msd wires or the stockers? Also, do you need to use cats for this swap??

MSD, the bendable ones. No cats.

[Puropedo]

Thanks for the advice dudes, this place if full of intelligent cool people!!!

[Prathbun]

ttt

Can anyone tell me if the Performance Online LS motor mounts and the Performance Online transmission cross member (for a 4L60) will be a direct bolt on afair??

Thanks!!

[Shon]

http://www.performanceonline.com/sto...cat=455&page=1

If this is the kit you are talking about it is incomplete for the job.
you will still need the LSx mounting plate, I used the Transdapt kit, and I am using the stock motor stands. As for the trans crossmember, it MIGHT be a bolt in affair, depends on the location of the trans mount, my 4l80 sits about an inch from any mounting locations of the Xmember so I am cutting and adding material to the xmember instead of redrilling the frame, b/c my cab is still on the frame and can not get to the upper frame to drill the holes.

And since I am in the middle of this swap (see sig for link), think about how you will deal with the shifter linkage.

These are the mounts I am using, I bought this set up but do not need the motor mount that came with it (on left of the 2 pcs pictured), should have gotten the other part number and the kit you referenced has these same mounts that you need with those tubular perches. if you need the other part number PM me and I will find it:

Originally Posted by Prathbun

ttt

Can anyone tell me if the Performance Online LS motor mounts and the Performance Online transmission cross member (for a 4L60) will be a direct bolt on afair??

Thanks!!

[Hart_Rod]

Originally Posted by Shon

http://www.performanceonline.com/sto...cat=455&page=1

If this is the kit you are talking about it is incomplete for the job.
you will still need the LSx mounting plate, I used the Transdapt kit, and I am using the stock motor stands. As for the trans crossmember, it MIGHT be a bolt in affair, depends on the location of the trans mount, my 4l80 sits about an inch from any mounting locations of the Xmember so I am cutting and adding material to the xmember instead of redrilling the frame, b/c my cab is still on the frame and can not get to the upper frame to drill the holes.

And since I am in the middle of this swap (see sig for link), think about how you will deal with the shifter linkage.

These are the mounts I am using, I bought this set up but do not need the motor mount that came with it (on left of the 2 pcs pictured), should have gotten the other part number and the kit you referenced has these same mounts that you need with those tubular perches. if you need the other part number PM me and I will find it:

Have you tried using the factory 4L60/80 tranny mount? It's got only 1 stud and sits about 3/4" further back than the normal mounting point of the TH400/350 transmission mount.

[Prathbun]

Thanks for the replies!!!

Yes, I have the TD Trans Dapt engine plates and mounts. Those exact one and they fit great on a 2004 5.3 engine. I cant remember if i had to message the holes some or not but they work great.

As far as the cross member from Performance Online, according to the tech support, I will need to re-drill some new holes if I using a 4L60 or a 700r trans.

Dang!! I'm looking for a cool looking, bolt in cross member.

[Shon]

Originally Posted by Hart_Rod

Have you tried using the factory 4L60/80 tranny mount? It's got only 1 stud and sits about 3/4" further back than the normal mounting point of the TH400/350 transmission mount.

I do not have the 4L80 trans mount, did not come with trans, and I purchased a ES poly bushing to use, I thought I had looked up the part number for the trans/year vehicle I got the 6.0/4l80 from but will go back and look but the ES unit is the universal one like I use on 4th Gen F-bods and most other GM stuff. BUT if the stock one sits back further I will go find one, not opposed to stock rubber unit....

*edit*
I have a 4l80 mount on order, local parts counter did not have one in stock, will pick it up Tuesday PM. I will go home and see if it fits.
I also started wondering if the ES poly mount could be turned and it work, instructions say to have the 'bubble' towards back of truck but I can not see structurally why that would matter, now it might get in the way if removing trans pan but otherwise not sure why it matters. if someone knows structurally then please post up.

*edit #2*
turning the ES mount around did not work. I will try the stock 4L80 mount tomorrow night

[Prathbun]

Alright, I have finally solved my transmission cross member problems. I installed the OEM (2004) transmission mount that came with my transmission, I lined up the '69 cross member and drilled one single hole. Bingo!!! Tightened up the bolts and that was it. The (2004) OEM transmission mount does set back further than the one I was trying to use and the hole that I need was just forward of center in between the 2 existing holes. I spent more time doing the research and postings than it took me to do the job!!