veee8

iTrader: (40)

Trying to clear up a detail. I have a TH400 and a LS1 TCI flexplate. I know it has dual bolt patterns, the small pattern and 4L60E I believe. I have a converter in there now that has the small pattern, now I am looking at a different converter, and need to know what will work. If an aftermarket TH400 converter has only 1 bolt pattern, is it going to work with this plate? Or do I need a TH350 converter? Talking about converter bolt pattern only.

veee8

iTrader: (40)

bump!

veee8

iTrader: (40)

Anyone?

billybadd

iTrader: (21)

th350 & 400 are the same bolt pattern. Either bolt pattern should work with that flexplate.

veee8

iTrader: (40)

I was under the impression that the 350 generally had around a 10.75" bolt circle, and 400 had a 11.25+??? Not sure though.

Shoaf85

iTrader: (9)

Tell whoever is building the converter that it is for a LS1/th400 car and they should be able to add the spacer onto the front of the converter and the standard 400 bolt pattern will work with that flexplate!

veee8

iTrader: (40)

Well the converter I have now has the "350 small bolt pattern" and bolts right up, the other pattern on the flexplate is for a 4L60E. Now as I understand it, there is another 3 lug bolt pattern for the 400 that is the "large bolt pattern"
I see a lot of converters out there that are labeled for a 400, I wonder what these pattern most aftermarket converters have????