5.3/ Th400

[lechez71]

im trying to gather as much info before i swap in a 5.3L in my 82 c10. my question is i have a Th400 that i want to use with the 5.3L, will the th400 bolt to the ls motor and which flywheel will i have to use? are the converters the same size. oh and the motor is out of a 03 tahoe. any help would be appreciated.

[sandking]

The trans will bolt up no problem. But one of the holes wont line up. 5 out of 6 bolts will hold it in place without any issues. I am not sure on the flywheel, but they are only $100.00. I used an ATI SFI Flexplate (I dont have part numbers). Converters also not a problem. I used a 10" converter on my last build (LS1) but should be similiar.

[sandking]

Any questions, email this guy, he can answer anything you may need CLICK HERE That is the guy who built my last trans, you can see it in action in their videos, the offroad trucks (the one with the lights over the cab).

[lechez71]

thanks i sent him an email with the questions, hopfully he will answer my questions. but if anyone can help me out here i apriciate it. the swap is kinda making me think twice, from the info i have gotten so far its takes alot of money for a swap like this, i dont know if i should go old school GEN 1 carb setup, i rather go ls1 setup but i dont know if i can handle the job myself. my plans are still for an ls1 motor but im going to study everything well before i get started.

[lechez71]

can anyone help me on parts what is needed to mount the two together, i have a 03 5.3L flywheel the stock TH400 flywheel and converter. will any of this work.

[1_fastsilverado]

You should Pm Virgil (mean05) or Moze (Damnyankee) about this, they are both in the process or switching over to 400's, so they would have an idea about the flexplate issue and give you some advice!

[lechez71]

sweet i forgot that virgil was doing the 400 swap on his truck.

[mean05]

use the 03 flexplate and starter and have a converter made with the ls back and the th400 hub, i had Art Carr build me one for my setup...everything else works fine, your 82 would have came with a th350 or 400 so the DS and tranny mounts should stay the same

[SNEEKY]

so your saying that a regular th400 converter wont bolt up to a ls syle flexplate? dont tell me that! i dont wanna have to buy another converter as well.....!!! if i doo im going with a 4k stall and say screw it lol dont be intimidated by the fuel injection. i was at first also, but its way more simpler than you think! and you will love it sooo much more!

[RedHeartbeat]

you can buy a crankshaft spacer, longer bolts and flat flywheel from crateenginedepot.com to use a stock TH350 or TH400 converter on an LSx type engine. 99-2001 6L engines have the extension built into the crankshaft already.