taqwache

i haven't tryied it yet but i heard of people on this board not using adapter plates when converting to 400's and 350's. they said that you just dont use the one missing hole on the passenger side and you end up with 5 bolts. will the other tranny holes just line up and will it be centered? also the other day i pulled of a flywheel out of a 6.0l engine with a 4L80E tranny. this converter has 6 holes but three of them line up with an old style tranny converter (400, 350, powerglide) and the thing of course bolts up to a LS1. so now i am wondering if i can use this flywheel and just bolt up my 400THM straight up to the motor and use the less expensive converters with out having to drill my flywheel. also how much shorter is the driveshaft if any from a 6-speed? if it is close then i can just change the yoke on my original shaft. if all this is true than i can save a ton of money since i already got a built 400THM with a 4000 stall converter for nitrous i can use.

taqwache

anybody got any thoughts on this topic

taqwache

i know this is an old tread but it never got answered. has anyone tried it?

LS1x2

iTrader: (11)

You don't need that money-making adapter plate. You will be fine without it. Not sure about the flywheel fromt he truck. I had to purchase a flywheel from a 98 ls1 for my 01 ls1. You can running a normal th400 converter. Not sure on the DS. The stock A4 DS fits with a 9" tailshaft th350.

DR.BOOST

I used my stock 2000 LS1 flexplate with my Turbo 400. You need to buy a Turbo 350/400 converter with the smaller bolt pattern and it will bolt right up to the stock flex plate. BTW.....I bolted mine straight to the block also.

MacGyver

iTrader: (5)

I dont run a plate and I have a brake. Now I dont run that fast yet. But I know that GerogeC doesn't run a plate and has cut 1.3x 60's on the tranny brake with his setup and has seen 9 second passes. Just food for though. How much more strength can one more bolt provide really.


Will

GeorgeC

IMHO, the adapter plate is totally unnecessary... The only thing I've broken are bellhousings, and it has nothing to do with the absence of an adapter plate...

Jay Johnson

iTrader: (16)

He he he.

I am selling a TH-400 conversion for F-body's.
Pulling my M6 was getting old especially when it
would not perform even with high dollar parts, and
I was not about to get royally ripped by "Big name"
tranny shop conversions.

I did my own conversion and I don't use an adaptor
plate.

https://ls1tech.com/ubb/ultimatebb.p...=009065#000000

Up for sale is almost every single part needed for
a F-body TH-400 conversion, even the shifter and
driveshaft.
Only thing I can't easily pull out of the car is
the BMR short tq arm(welded crossbar).

I'm selling this proven setup so that I can make
another conversion with a more extreme tranny setup.

Jay Johnson
jayjohnson@rocketmail.com

highgmc

If not using a trans brake I'd skip the adapter plate to gain the extra bolt.

If using a trans brake I'd definately use the Yank plate for the extra bolt. <img border="0" alt="[driving]" title="" src="graemlins/gr_driving3.gif" />

taqwache

thanks for all the replys. [/QUOTE]I used my stock 2000 LS1 flexplate with my Turbo 400. You need to buy a Turbo 350/400 converter with the smaller bolt pattern and it will bolt right up to the stock flex plate. BTW.....I bolted mine straight to the block also. [/QUOTE]that sounds good. my converter has small and large bolt patterns. did any of you guys need to add a spacer or did the converter just line up?