transamfreak01

iTrader: (8)

I purchased from Texas speed the tci flex plate 399753 that is going to my 408 to the th400. My question is they said it is th400 specific but it comes with a crankshaft hub adapter. Since they said it was for a th400 I didn't think I would need it. I called them and even they were unsure if I needed it, and if it goes between the motor and flex plate or between the flex plate and converter...... I would assume it goes between the motor and flex plate but those flex plate bolts don't look long enough at all. Anyone got an answer?

Burken01

iTrader: (88)

If you use a regular th400 converter you'll need the pilot extender to extend into the Ls crank..

If you get a converter made that is a th400/ls1 specific, most vendors will build it with a th400 front and ls1 rear pilot so no adapters are needed

That flex plate isn't just for th400's, it's what anyone will use whether it's a th400, th350, powerglide, 700r, 4l60 etc. My guess is they add the adapter not knowing which Trans/converter you will use

forcd ind

iTrader: (7)

As said, you need the spacer if using a standard 400 converter snout.
The FP has a spacer on the back that lines up the FP/starter, but your still short on mating up the converter. Sometimes you have to add spacers bet. the FP and converter pads to get correct pullout.
I remember when I used the FP on my stroker, It came with metric bolts, my crank (Scat) had American threads, so I had to search for ARP bolts to fit

transamfreak01

iTrader: (8)

Gotcha. Ok I'll call fti when they open and ask them and then I'll check back in

transamfreak01

iTrader: (8)

Ok so I just talked to them and they said it doesn't come with the ls1 rear pilot but all I need to do is put a 1/8" washer on the crank? Still unsure about that hub adapter though

transamfreak01

iTrader: (8)

I am on my phone so I can't really upload pics but here's the link for the flex plate and that hub adapter is in there http://www.texas-speed.com/p-2500-tc...flexplate.aspx

I want to get this right bc I do not want to pull this trans again

Circle-D_Brian

The tci 399753 flexplate features a 10.75" and 11.06" pattern. We call these the LT and the LS patterns.

Most TH400 converters Feature an 11.5" pattern shared by the 4l80. All you need to figure out is whether or not your converter will have one of the two patterns on that flexplate, and how much the pilot extends beyond the converter pad. Your standard 400 pilot will extend appx 1/4" beyond and require the pilot extender that came with your flexplate, and your LS specific pilot will be closer to 1/2" beyond the converter pad. You would not use the pilot extender if this is the case. Hope that helps.

-Brian