Boosted Firehawk

iTrader: (11)

FIrst off I am putting a th400 behind the 5.3. BUt Im having issues trying to figure out what flexplate I need.
The block is a 05 and I hear different stories about flexplates and spacers.

SO what do I need to make this bolt up? I have a chevy th400 and will order a converter to fit the 5.3L Ls engine but what is needed to make this work properly? I would like to order this all today.


Next ? is Should the car be tuned with a MAF setup or Speed density on e85?

Huron Speed turbo kit

westTEX26

Jegs sells the adapter pretty cheap. All it does is move the flex plate closer to the converter.

djfury05

iTrader: (30)

Speed density.. lose the maf

Boosted Firehawk

iTrader: (11)

part numbers or links help?


reason why?

red 95 t/a

http://www.speedwaymotors.com/LS-Cra...ter,64394.html

I'm assuming your 5.3 had a 60e. Behind it factory so it should have a curved flexplate That's all you need

djfury05

iTrader: (30)

Much easier to tune.. I've read that in higher boost the maf will cause issues too not sure what though didn't research that deep in it.. driveability can be just as good as with a maf there

Boosted Firehawk

iTrader: (11)

The engine has NO flexplate at all so I need one.

SO will a stock flexplate work from a 5.3 with a 4l80e?
OR do I get aftermarket?

Boosted Firehawk

iTrader: (11)

I never had a flexplate on my engine when I got it.
SO If I use that adapter up above can I use a flexplate that came off my buddies lq9 engine? He is not using that lq9 flexplate will it work with this sleeve, my engine and a th400?

WheelsUp84z

iTrader: (14)

I run the TCI flexplate for the ls-th00 combo. Deffinately speed density. You can do a MAF with boost, but it limits the setup to an extent. Unleashed ran a man on their vette but I think it was draw-through.

Wicked69

If the flexplate is curved I believe you can use it. You just need the spacer. I think I have one somewhere in my garage. I also have a flexplate that would work if your not sure. If I have it you can have it for the cost of the shipping and a six pack of beer. The spacer and flexplate.

Wicked69

I would also have to look again but I think if you use a LS style convertor with the longer snout and you tell them it is for a TH400, I don't think you even need the spacer. I think you only need the spacer if using a TH400 convertor and NOT the LS style convertor. I would have to double check. I will look at mine tomorrow. My engine and trans are currently out of the car and apart. I also run a TH400 behind a 5.3. I used the stock flexplate and originally used the same convertor I had and so I had to use the spacer and modify the holes in the flexplate. Later I got a LS style convertor and don't believe I use a spacer anymore. I'll check and report back tomorrow.

Boosted Firehawk

iTrader: (11)

cool, either way lmk.

I did hear something about ordering the converter for a ls engine with the use of a th400.

red 95 t/a

With a curved flexplate use that. Spacer. Depends on what your buddy's lq9 is out of. Chances are it had a 65e behind it so it would be a curved flexplate. The only ls motors that had 80e behind it come with the flat flexplate with the factory spacer between the crank and flexplate.
From what I see this subject gets over complicated all the time. Here is your options.
#1 curved flexplate is for a 60-65e (300mm) converter. Use the spacer from speedway if you want to use a "old school" converter.

#2 factory flat flexplate with factory spacer only came with a 80e because the 80e is a "old school" non 300mm converter

#3. Have a converter built for for ls

Of course this all depends on if you have a th400 converter already that you was going to use. Just have to weigh your options and decide how much money you want to spend.
I am using a 5.3 and th350 in my mustang and using the factory flat flexplate with factory crank spacer from a 80e setup. Hope this helps you

Wicked69

Yeah. No spacer on mine. If you want to use your same convertor I can look for my old spacer. I would get a PTC convertor for a TH400 with an LS snout like I did. The convertor was a huge difference. My car ran a 100mph with my old convertor and 118mph with the PTC convertor. (1/8th mile) A whole lot less work. If you use your old convertor you will also have to modify the holes on the flex plate like I did. I had success doing it but several others wiped out bearings down the road.

Boosted Firehawk

iTrader: (11)

Im going with PTC for sure. Every car I own has a PTC converter. I love them

SO get a ls style converter for my th400 and use a flat or curved flexplate with NO spacer?

robsquikz28

iTrader: (246)

PTC is the way to go and SD tune will be a lot better

denmah

iTrader: (2)

stock ecu? definitely go with a Map/SD OS upgrade

denmah

iTrader: (2)

i run a stock 6.0 flexplate/spacer/bolts in my th/glide swapped cars, with regular style small block converters.

some places will make your converter to fit the 60e bowed plate, you can also get spacers from places online etc...

honestly if you are gunna get a converter ask the place building the converter what your options are and go from there.