ls1 trannys???

[DMONOTJR]

i know the ls1 block is a new design block, but would a th350 bolt up? is the bolt pattern the same or different from the earlier 350 blocks?

[ZR1BLAZER]

im almost positive the bellhousing is the same?

[ZZ4Blazer]

The bellhousing is just about the same. Its just missing one of hte bolt holes. The one on the top, right side of the bellhousing.



It bolts up no problem, just gotta leave that one hole empty. BUT, Im pretty sure you need a spacer or some kinda special flexplate to run a regular sbc tranny on an LS1.

[CavemanFabrications]

yes, one tab on the top of the block is left empty, but you dont need it. grade 8 bolts work fine.

i have done this conversion before, ive never seen it replicated though. i had to have a special flywheel made, and sent to 3 machine shops. i can tell you anything you need to know about the ls1 t56 and sbc combinations. i built a stout 355/t56 powered 2nd gen mazda rx7 last year. build threads are under username sliderx7 around the web.

consequently, my custom 02 t56 to gen 1 sbc flywheel is for sale, as i have parted out most of the build.

it cost me $615 to have made, pulled from Spec's production line. all you need to do is get a ls1 clutch/PP, and youre off. depending on what year your tranny is, you may need a pre '02 input shaft. its a pretty neat combo. email me for info cavemanfabrications@gmail.com

[Jeffyboy]

I'm almost positive they make special torque converters for Gen III/IV to Gen I transmissions. It might have been Car Craft that had this as a feature a couple of months ago.

[Scotty_S-15]

All of the above is true. You can use:
* Spacer
* Special converter (not really "special", just "specified for the intended use")
* Special flywheel

As I understand it, the spacer is no big deal, and not a problem. Ah, found a link with some info: Scroll down to near the bottom of the page, they have the spacer with some details.
http://www.redrider.us/th400_.htm
.
.

[Rinkrat456]

You can pick these parts up from the dealership, they are factory GM part numbers.

Spacer
12563532

Longer bolts, 1 package of 6
12563533

[stevo67]

yes, one tab on the top of the block is left empty, but you dont need it. grade 8 bolts work fine.

i have done this conversion before, ive never seen it replicated though. i had to have a special flywheel made, and sent to 3 machine shops. i can tell you anything you need to know about the ls1 t56 and sbc combinations. i built a stout 355/t56 powered 2nd gen mazda rx7 last year. build threads are under username sliderx7 around the web.

consequently, my custom 02 t56 to gen 1 sbc flywheel is for sale, as i have parted out most of the build.

it cost me $615 to have made, pulled from Spec's production line. all you need to do is get a ls1 clutch/PP, and youre off. depending on what year your tranny is, you may need a pre '02 input shaft. its a pretty neat combo. email me for info cavemanfabrications@gmail.com


What you have posted is the opposite of what the OP is asking, but good info non-the-less.

Also, there is a Classifieds section if you want to post something for sale.

[carshop]

When you order a converter for a ls application it will have a extended snout length so it supports in the back of the crank flange like stock, also depending on company the bolt pattern will be modified for the ls metric bolt pattern.
You also need to make note of which flexplate you are running, The truck flexplates are non dished in applications that came with 4l80e's and came with the spacer behind it on the crank flange.
The F body and 5.3 engines had a dished flexplate that will require the use of a custom converter or the gm spacer combo in order to run your non ls specific converter (some light flexplate machining is required.
Tci also sells a sfi approved flexplate that has the patterns already drilled for both metric and standard style converter bolt patterns, this unit comes with a spacer for non ls specific converters also...

[Ryoung68]

Good post Carshop all that is missing is the part numbers, good info, thats what this site is all about. :headbang:

[carshop]

http://www.carshopinc.com/images/TCI%20399753.jpg
799753 tci