ly6 6.0 which transmission

[1981 chevy10blazer5]

ok guy i need a lil help on going which route with my truck i have a 81 stepside 4x4 and want a ly6 which as you know has ls3 heads im wanting to change the intake to give it a old school carb look but want to stay fuel injected so i was planing on buyin a holley mid rise intake so i could put on it a 4150 style thorttle body but my main concern is which transmission should i go with i have a 700r just needs a rebuild or buy a th400 could a 700r handle the power this truck is gonna be my daily driver amd every once in a blue give it a hell not to much though since it will be my daily has anyone had this conversion any pics or concern you guys had would be greatly appreciated

[mongocanfly]

I would go t400 just because...although a 700r4 can be built to hold....you will need a flexplate to put either behind the LS...
you can use a holley 300-137 intake on it and you can have a adapter made to mount your ly6 throttle on top...check out dayj1s build here...http://67-72chevytrucks.com/vboard/s...d.php?t=668385

[1981 chevy10blazer5]

i was looking at the holley thorttle body for my setup

[mongocanfly]

I had not seen those...that's a good looking unit...im gonna have to read up on these...

[Bandit130]

[1981 chevy10blazer5]

hows it going man

[Edahall]

Since this is a daily driver, it'll be much nicer to have overdrive so go with the 700R4 or better yet, find a 4L80e.

[1981 chevy10blazer5]

ya it would be nice but my main thing would be to keep it non electronic transmission so either 700r non electronic or a th400 i really dont want to bother witg extra wiring if i dont have to

[PunishedC10]

You mentioned this is a daily driver. One thing that would help determine which is best would be your top speed while driving, what rear gears you want and your overall tire height. You don’t want to cruise down the highway for 3 hours at 75mph and be running 4000rpm. If you want to run this thing down the highway at 65-75mph I would suggest going with a 700r4, 4l60e or 4l80e. You will want an overdrive trans. There are calculators online that can determine the rpms based on your trans choice, gear choice, and tire height. Keep in mind, the crank space/flexplate, torque convertor pattern when choosing your transmission. I am running a ‘98 LS1 with a 4l80e. I am using a TCI flexplate and my torque convertor came from Circle D out of houston. They made my torque convertor with the spacing and bolt pattern to work with the ls1 crank and 4l60e flex plate.

[1981 chevy10blazer5]

my blazer has a th400 with a 5.3 out of 2011 chevy silverado all i did was buy a flexplate from a 6.0 which year i dont know but i went to my local transmission shop and thats what the guy gave me i put it on and it bolted right to the stock turbo 400 convertor both my truck have 33 inch goodyear wranglers i live like 30 min from imperial sand dunes and like 1 hour from glamis sand dunes so that would be the farthest i drive besides in town to my local stores and stuff so do i really need high speeds probably not would i like better gas mileage heck yes but im sure the 6.0 are not eco friendly anyways i just dont want through on a 700r4 and have it burn up i know forsure the th400 can handle the abuse

[RotaryRocketeer]

Don't overlook the venerable, and often forgotten, 200-4R. They can be built to handle the power without much trouble, have a better overdrive ratio than the 700R4 or 4L transmissions, and aren't very expensive. No electronic control and they're an exact swap, dimensionally, for a TH350. Just gotta move the crossmember back a tiny bit or make a rear offset trans mount. Everyone may not agree, but I'm a believer. Just my $.02.

[SunSoaked]

Cheers from a fellow "Yuman". I'm about to pull a fresh th400 out of my 85 k20 to make room for the 4500. Pm me if you want to meet. I just converted the engine to Vortec heads, cam, headers and Holley Sniper. She runs like a raped ape and purrs like a kitten.

[1981 chevy10blazer5]

by anychanse do you still have the tranny

[74CustomK20]

Originally Posted by RotaryRocketeer

Don't overlook the venerable, and often forgotten, 200-4R. They can be built to handle the power without much trouble, have a better overdrive ratio than the 700R4 or 4L transmissions, and aren't very expensive. No electronic control and they're an exact swap, dimensionally, for a TH350. Just gotta move the crossmember back a tiny bit or make a rear offset trans mount. Everyone may not agree, but I'm a believer. Just my $.02.

They are good trans, but he's 4x4 and i think those are only in 2wd right? I'd go a built 700 or 4L80. If you have fuel injection a 4l80 isn't a lot more wiring, plus you won't have to worry about brackets and little stuff for the throttle valve cable.

[RotaryRocketeer]

Originally Posted by 74CustomK20

They are good trans, but he's 4x4 and i think those are only in 2wd right?

Good point here. I overlooked that. Could always go with a divorced t-case setup, but the tail section is non-removable and you’d have some work to do.

Also, this thread is pretty old. Guessing this project died in the planning stage lol.