Thanks in advance for any help. I have read through the stickies, posts, and tons of sites about a th400 swap to a stock LS1 and I have a few questions due to some wrong Info I have come across. I have a short tail th400 and have been trying to figure out exactly how to get it all to work. If I understand correctly, all I need is a TCI 168 tooth SFI flexplate (#399753), a GMPP flexplate spacer (#12563532).

I just thought Of something. The GM spacer was used to fill the gap between 4l80e's and 5.7-5.3 truck cranks. So the pilot should be different. Should I use the spacer from TCI? I have emailed them a bunch of questions, but they haven't replied, been a week or soThen while reading the stickies, it says

Quote:

the TCI spacer can be replaced with one with a longer nose. This is because a standard converter doesn't have a pilot long enough to engage the back of the crank.

So then, what one should I use?

I want to use a standard th400 torque converter because it is cheaper and it’s easier to sell if needed in the future. Now the GMPP spacer moves the flexplate out .400. Is there any concerns about moving it that far from the starter? Does that spacer have the center extended enough to accommodate the pilot in a standard th400 converter? Otherwise do I need a pilot extension in addition to a flexplate spacer? If so, what did you use? It looks like the GM spacer has the pilot extension built in because this is needed to help center the torque converter.



What did you do about a kickdown switch? Did you mount it to your pedal like the Chevy trucks and vans? Or has anyone used the kickdown switch from summit racing that utilizes your throttle cable?

For now my mods are a ported TB, LS6 intake, Hooker Super Comp LTs, ORY, Magnaflow catback, lid, smooth bellows, MSD wires, SLP flopack, coolant bypass, air-egr-rear o2 delete, th400 (going to be stock gearing, refresh, B&M race overhaul kit, B&M Shift kit, forward valve body-vacuum modulated-want to keep stock shifter and shift positions), Moser 9” w/ 4.33’s, 31 spline axles, Detroit Tru-Trac –non abs. So I have to figure a stall to get for this setup. I also plan to use my stock shifter. (I plan on doing a 408 in a few years, cannot swing it in the near future.), UMI LCA's, UMI Tunnel mount TQ arm, 3 point weld in subframe connectors (on the car for 2 years and never welded yet )

So this is what I have to work with. Please let me know if I have this stuff correct because I want to have all of this complete for spring so I can figure out a drive shaft. I have read all the stickes many, many times.

Thanks for you time

Mark jr.

 

You shouldn't need a spacer if you are using that flexplate from TCI. Thats mainly why this product exists, so you don't have to use a spacer. Thats my take on it anyway. I just bought the TCI flexplate, and told my converter builder (Yank) which flex plate I have, then Yank built me a converter to fit., No drama whatsoever.

 

From what I have read, you still need the flexplate spacer. The TCI plate has holes for the 4l60e type converter and holes for the standard th400 converter. There is soposed to be a spacer that comes w/ the flexplate from what I have heard. From what you are telling me, it sounds like Yank is building you the converter w/ the longer pilot extension so you don't need the spacer (4l60e type TC). I'm not paying $845 to do this, it can be done cheaper. Unless I have it wrong Not saying you are wrong, just that I have read sooo much my head is spinning, lol. It would be easier if I could get TCI to respond to an e-mail though. Thanks for replying.

Anyone have it in the car final w/ TCI plate and using a standard th400 converter?

 

you must use the spacer. to my understanding that is just an sfi aprroved flexplate. and mine came w/ the spacer. here you go. cheap fix to your problem

http://store.summitracing.com/partde...5&autoview=sku

 

That is exactly what I thought. All it looks like is a regular flexplate w/ the extra holes for a standard th400 torque converter, and it's SFI approved. Now w/ the Hughes spacer, does the pilot on your torque converter extend into that spacer to help center the converter? Or do you still need a pilot spacer? If so which one? I'm assuming you ran a standard th400 Torque converter? Sorry but I think I am over thinking this

thanks for the help, I appriciate it.

 

the spacer is all you need for a old school converter to ls motor

 

so if you use the spacer can you use the standard ls1 flexplate and just bolt the th400 behind it? the trans cross member also has to be moddified i think how? and depending on the tranny the drive shaft also has to be lengthen'd.

 

yes on all the above

buy a bmr crossmember is the easiest and cleanest
shorten or lengthen driveshaft

 

cant I go with GM Spacer instead of the Hughes? cause some people are saying the GM spacer can be taken off, but the hughes mut be hammered in and once in can't be taken out...

?!

 

Im lost, and I want to order one, which one should I go with please help!

does it go this way?

Hughes + LS1 98 flexplate + th400 torque

GM spacer + TCI flexplate + th400 torque

Dosn't it work like this:

GM spacer + 98 LS1 flexplate + th400 torque?

 

Good God...it's threads like this that confuse the **** outta people.

 

Wow is this an old thread I started. Red83 helped me out greatly with this project. Mines all installed and driveable (chasing driveline vibrations) I decided to do it simple:

-TCI flexplate (#399753)

-th400 torque converter (with LS1 pilot extension-most companies this should be free)

-custom length driveshaft (you must measure this one out yourself)

That is it. Very simple. I was really overthinking this project now that I am reading the old questions that I have.

mark jr.

 

loool, seriously, Im doing what you've done along time ago... I'm over thinking it...

I got a th400, but it looks different from other th400's first the oil pan is not as deep as the other th400's second of all, the torque has a different look than other th400's... this is whats written on the tag

74-NA 11-84

Anyone encountered such a th400 or has idea what I've got myself into? lol

 

Well, the pan is nothing. Sounds like you got the small pan. I went to a junk yard and pulled a deep pan off of a th400 for $3. They hold approx. 2 quarts more that the smaller one.

I have about 7 th400's at home to look at and some torque converters look different than others. Make sure it is a th400. The pan should kind of resemble the state of Ohio.

I no longer have the original tag from mine since the company that I had build it removed it. I will look in the garage at a few I have. Either you have an '84, or a '74 tranny. I have one that I know is from '69 and one from '77, so I will be able to verify what year yours is. Here are some pics of mine from my on-tech photo album so you can see any differences:

 

I guess I did have the smaller pan, and yes I was sure its a th400, because the pan does look like the state of texas... but I returned the transmission, and I'm going for another one... I already have a R154, and Im trying to get that to fit, but till now I'm getting no proper info on the swap... I really want a manual...

 

I found an adapter for the R150 and R151 on a small block chevy, I contacted the company, and Im checking whether it works for the R154, I don't know why anyone would ever put an R151 or R150, cause they are weak, the R154 is basically unbreakable... from my experience with it... my friend has a 450hp car on a stock one with a 5 puck ceramic clutch... if they confirm that the R154 has the same bolt pattern Im going that route...

 

will this torque converter work with the GM spacer to fit into the LS1 5.7L I have... cause I've seen different torque converters, can anyone confirm...?

 

anyone?

 

The gm spacer would be the route I would take or get a custom stall converter with the correct pilot on it. To me it just makes sense.

The converter in the picture was what I would back in the day call a th350 converter. This was a very common style for th350 units in cars. However the 400 and the 350 converters are very much the same. Reason is because both units have the same spline counts for the stator, input shaft and the pump. Vince B

 

oh what about the other part of the torque converter, the part where it attaches to the Flexplate, is it similar to the th400 big torque converter? because I think thats the only case where my adapter will work, cause the adapter is designed for the th400's torque...

What do u think?