What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

TnA Engine Crossmember Kit

TnA said:
Yeah, in my research, the only real logical option in our trucks are the brackets that mount the compressor up high on the passenger's side also. Notching the frame for the factory compressor isn't an option in the trucks, due to the length of the compressor and the interference with not only the frame but the engine crossmember too. I don't think that notching both at the same time is a good idea at all. The bracket kits that I've found so far use a different compressor than the factory one that comes with the LS, which adds yet another item to purchase if keeping the AC system. I might look into making a different option for all you guys, but it's not high on the list at the moment. I'll keep you posted though!

-Darren
Click to expand...

Hey Darren,

I think I may have found a solution for the low mount A/C problem when doing this swap on our trucks over at 67-72chevytrucks.com. It looks like if you add some plate and shift the passenger side engine stand back a little, you can run the LSx A/C in the stock lower position. The truck in the pictures is an '85 2wd but I'm guessing the frame and engine crossmember are the same as the 4wd square bodies... Since you're building a whole new crossmember with motor mounts just for the LS swaps, I thought this might be some good info for you in case you want to incorporate some of the ideas in the prototype you're working on... Here's some pics that I'm borrowing from the thread over there (the link for the source will be posted below):

glock35ipsc said:
(As viewed on the drivers side of the block)
Enginemountlocations-3.jpg


From MY experience, #2 worked best for the 73-87/91. Let me describe my original setup:

1985 GMC 1/2 ton SWB 2wd. 305/TH350C. The TH350 had a 9" tailhousing.

By using the #2 plate, all I had to do to mount the transmission (a 4L60E) was slide the trans crossmember about 2" and drill a couple holes on each side. Easy stuff.

These plates put everything in a position to where the shifter linkage was in the proper place, and the driveshaft installed without modification. I am using a mechanical clutch fan, and it sits centered front to rear, as well as up and down, within the fan shroud.

The one issue with using the #2 plates comes when you are going to use the LS's AC compressor in it's original low location. Here is the problem I ran into:

SP1-1.jpg


Basically, the forward ear of the adapter plate interfered with the compressor bracket. The green triangle is where the clam shell mount from the old SBC was supposed to go. I determined that moving it to the location of the red triangle would solve the problem. Then cut the excess off at the white line. Essentially, I would be modifying the #2 type plate to be just like a #3 plate.

attachment.php


attachment.php


Now everything will fit:

attachment.php


Then I added an extension to the engine stand so that the rubber mount would have something to bolt to:

attachment.php


attachment.php


Another option would be to add a bracket to the crossmember, and move the engine stand back about 2". Member menace121978 did this with his. He welded a piece to the crossmember. You might be able to do this with a piece of angle iron that is bolted to the crossmember as well:

attachment.php


attachment.php


attachment.php
Click to expand...

glock35ipsc said:
Yeah, I guess I left that important little tidbit out! :lol:

AC compressor in it original location, no frame notching, and no aftermarket AC relocation kits required.

P1010202.jpg


P1010628.jpg


IMG00059-20100418-1651.jpg
Click to expand...

Here's a link to the thread over there for anyone that wants to read the whole thing: http://67-72chevytrucks.com/vboard/showthread.php?t=413855
 
63chevyll said:
Those are good ideas, but I.always hear you cant get the compressor out once its in there
Click to expand...

Those are some good ideas, but in addition to not being able to get the compressor out - he moved the engine forward a little, and also moved the side pieces of the engine crossmember backwards what looks like quite a bit. That's much easier to do with the factory 2wd crossmember, but in the case of my HD replacement 4wd crossmember, or even the factory 4wd one, it isn't quite as simple. That article brings up some good ideas, but I still don't see a logical way to do it on the 4wd trucks, especially with my HD crossmember. Sorry guys!!

Also, my crossmember along with my new LS motor mounts keeps the engine at the same position in the truck so that it bolts up to the factory transmission *without* having to change trans mounts/trans crossmember location. This puts the back of the LS right at the firewall, but still clears everything. Also, I positioned the LS engine with my mounts so that the fan centerline is very, very close to factory small/big block location, so the factory fan shroud will still line up. All the "flat plate" style adapter mounts add height to the engine location and bring the high fan centerline even higher so that you'll have to mod your fan shrouds.

-Darren
 
63chevyll said:
Those are good ideas, but I.always hear you cant get the compressor out once its in there
Click to expand...

I can't speak from personal experience since I'm still a couple of months out from starting my swap but I haven't read anything about not being able to get the compressor out once it's in there. I re-read a few sections in that guys build thread and he never mentioned having any issues getting it in or out with the engine in place (just issues with lines and hoses). Of course I could have missed it too but here's a link to that part of the build thread if you want to check it out: http://67-72chevytrucks.com/vboard/showthread.php?t=350986&page=21. They did say that you had to use a compressor from a '99-'02 since they're a little smaller or had slightly different outlets than the newer ones...

TnA said:
Those are some good ideas, but in addition to not being able to get the compressor out - he moved the engine forward a little, and also moved the side pieces of the engine crossmember backwards what looks like quite a bit. That's much easier to do with the factory 2wd crossmember, but in the case of my HD replacement 4wd crossmember, or even the factory 4wd one, it isn't quite as simple. That article brings up some good ideas, but I still don't see a logical way to do it on the 4wd trucks, especially with my HD crossmember. Sorry guys!!

Also, my crossmember along with my new LS motor mounts keeps the engine at the same position in the truck so that it bolts up to the factory transmission *without* having to change trans mounts/trans crossmember location. This puts the back of the LS right at the firewall, but still clears everything. Also, I positioned the LS engine with my mounts so that the fan centerline is very, very close to factory small/big block location, so the factory fan shroud will still line up. All the "flat plate" style adapter mounts add height to the engine location and bring the high fan centerline even higher so that you'll have to mod your fan shrouds.

-Darren
Click to expand...

He did wind up having to shift the transmission crossmember back a couple of inches but I think the mounts he used set the LS engine about 1" forward so it's actually sitting where the original SBC would be sitting. It actually looked pretty sweet since he was able to re-use the '85 fan shroud with a stock LS mechanical fan and intake. I'm not sure but I think if you were to use a shorter 4wd 4L60E you may not have to move the trans crossmember back as much as he did if at all. I don't have a cherry picker and the extra space in my garage yet to start playing LS Tetris yet so I'm just spit balling and hoping something will be useful lol.

glock35ipsc said:
I went and saw a friend of mine today, and he had a clutch fan for me to use for mock-up. It has a broken blade. But he also thinks he has a good one, so I will swing by his shop on Friday and see if he found it. If so, that will save me some time on Saturday and some $$$ too. I also got the shroud to fit too, I had to cut a little around the air intake, but it all fits real nice, but I need to trim it a little more (where the Sharpie line is). The fan sits just right in the shroud.

P1010174-1.jpg

P1010175-1.jpg
Click to expand...

I know not everything is applicable or will be transferable to the crossmember and mounts you're doing but it sure would be cool if you could make a kit that would bolt in to a 4x4 and make everything look as factory as that guy did on his street truck :bow:

On another note, do you know what the distance from the bottom of the block to the top of your cross member is? I remember you saying you had over an inch of clearance but wasn't sure where you were measuring that from. I'm wondering if an LS4 pan would fit in there. They're a lot shorter in the rear but hang down more in the front where the crossmember is at... The LS4 pan is about the same depth as the F-Body oil pans but it holds more oil and is ~1/4 of the cost so I figure it's at least worth asking lol. Also, do you have any updates on your swap motor plates? Put me on the waitlist for those bad boys if you have one :thumb:
 
cyclic said:
I still can't find the info for the Vortec compressor, maybe I dreamed it.

But I did find this page - http://www.alangrovecomponents.com/LS.htm
Several options for LS engines.
Click to expand...

I think you may have seen it on that build thread I referenced above from 67-72chevytrucks.com When they were originally playing with it another member said he had gotten it to work with an early Vortec compressor but when he started checking part numbers it wound up being a compressor from a '99-'02 truck/SUV.

I know there are several sources for relocation brackets but most of them are too big/stick out too far off the engine IMO and they all cost a good chunk of change. I saw that Darren was working on an LS swap specific engine cross member and thought that if he could somehow incorporate the ideas from the other forum it would solve a lot of people's problems and I'm sure he'd have them flying off the shelf once people found out about them. All of the TNA products I've seen on here have all been bad ass and I can't wait to start throwing some on my truck.

sweetk30 said:
or this with closest looking to factory bracket and comp used even in out trucks . https://www.holley.com/products/ls_power/accessory_drives/

for the 80's up we had the r4 comp used from around 83-84 up so if you have that then its super easy to keep your ac .
Click to expand...

Yeah those Holley brackets are definitely the best option I've seen and are still cheaper than some of the other brackets and kits out there. Great quality and they look like they could've come straight from the factory. The only problem is they're still pretty pricey once you include their mounting kit, tensioner, pulley, etc and are not in the plans for people trying to do this swap on a tight budget like myself. Something that looks and works real similar if you have an R4 compressor (mine is an '89 so I'm covered there) is modifying the bracket from a pre-Vortec 4.3 V6 like they did here: http://www.maliburacing.com/forum/viewtopic.php?f=34&t=79059. I was able to pick up the bracket, tensioner, and idler pullies for around $30 last weekend at the local Pick-n-Pull so I'll be going that route myself unless I find something else before I start my swap.
 
For us guys that don't have access to tube benders and such, will you be able to provide the track bar as well?
Also, I'm going to be dropping a BBC in eventually. Can I make your crossmember work?
 
Last edited:
just making sure these are still available. Not a big fan of the $300 PacFab unit and don't want to spend $$ on the ORD one to have to mod it to work with an LS motor.

I have an LQ9 just waiting to drop into my 87, just need a crossmember. Love the idea of the panhard too.

Sent you a PM
 
4wheelinfury said:
just making sure these are still available. Not a big fan of the $300 PacFab unit and don't want to spend $$ on the ORD one to have to mod it to work with an LS motor.

I have an LQ9 just waiting to drop into my 87, just need a crossmember. Love the idea of the panhard too.

Sent you a PM
Click to expand...

PM Replied :)
 
Great turnaround! Thanks man. Ordered last week. Installed this! Just need to paint and reroute the hydro assist lines. Under full compression the lines impact the crossmember. Just need to rotate the cylinder and route the lines to the front.

Might just drop the LS in this weekend as a test fit

fdda9cdf02afe99839441a39636b1e3b.jpg
 
They fit on the TNA crossmember?

Did you already have them when you bought the crossmember?
 
If you guys are looking at getting one of the TNA crossmemebers you should check out their adjustable LS swap engine engine mounts while you're at it and save on shipping. I think there's a couple pics earlier in the thread that show what they look like. Kinda similar to the DIY4X ones but with slots added for adjustability. I bought a pair a while back and they're really good quality and super beefy. Unfortunately they're also sitting in the box while I finish gathering the rest of the parts for the swap... :whistle:
 
You must log in or register to reply here.

Latest Posts

Top Bottom