Lil advice.
Thread Starter
Teching In
Joined: Sep 2023
Posts: 9
Likes: 2
Lil advice. Lil back story. Had a 350 in my 81 squarebody. Did an 4.8 ls swap. Kept the th350c which has the 1 wire on drivers side of trans. Trans was always sluggish on takeoff with the 350 which was old and work out. Had 3.08 rear. Did the ls swap installed same torque converter which was already on trans. Still had light blue paint. Assuming that’s gm stick color. Changed out the tear to limited slip 3.73. Truck is still a dog til around 25 or 30 then feels like it’s got an acme rocket behind it. I’d like to keep the trans since it’s been rebuilt Called tci twice never got call back. Can anyone maybe point me in the right direction on should I get a new higher stall converter or anything that can help with the sluggish takeoff. Thanks
LS1Tech Sponsor
Joined: Mar 2023
Posts: 1,824
Likes: 1,162
From: BERWICK PA
Well I would probably jump it to a 2800 to 3200 stall speed , Trouble is does anyone still make a stall for the 350c ?
Otherwise I would consider a 4l60e or 700r4 swap get better gearing, stalls avalable, and better economy .
Otherwise I would consider a 4l60e or 700r4 swap get better gearing, stalls avalable, and better economy .
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Frank formerly of Performabuilt, Now just me, What can I build for you today? Call or message me. Click sig pic for my facebook
Frank formerly of Performabuilt, Now just me, What can I build for you today? Call or message me. Click sig pic for my facebook
TECH Enthusiast
Joined: Jan 2019
Posts: 677
Likes: 490
From: Roxana, IL
The TH350C for a V-8 used a 1400-1600 stall converter. That's the same stall that is used behind the 4.8L,5.3L & 6.0L engines. That is for the usual TMBX converter code anyway. The change to 3.73 should have made it better on the take off.
Because it still feels sluggish on take off after the gear change makes me ask.. Was the 4.8L cammed at all? If it was you need to know what cam and choose a stall accordingly.. A 4.2L trailblazer comes with a factory 2000 stall, the 4.3L S10/Blazer also comes with a 2000 stall. Both are factory issue like that.
Brake torque the engine and see what stall you have. Or just romp on the gas and see what it flashes to. The second option is not quite as reliable for stall because the engine will climb RPM as it drives off.
Because it still feels sluggish on take off after the gear change makes me ask.. Was the 4.8L cammed at all? If it was you need to know what cam and choose a stall accordingly.. A 4.2L trailblazer comes with a factory 2000 stall, the 4.3L S10/Blazer also comes with a 2000 stall. Both are factory issue like that.
Brake torque the engine and see what stall you have. Or just romp on the gas and see what it flashes to. The second option is not quite as reliable for stall because the engine will climb RPM as it drives off.
TECH Junkie
Joined: May 2012
Posts: 3,052
Likes: 716
From: Poplarville, MS
You may have a hard time finding someone who offers a higher stall 350c converter. You may have to send your converter in and have it restalled. You may try giving FTI Performance a call.
Whatever you do don't buy from TCI, they do not stand behind their products.
Whatever you do don't buy from TCI, they do not stand behind their products.
TECH Junkie
Joined: Dec 2012
Posts: 3,621
Likes: 1,335
From: Iowa
Any converter manufacturer should easily be able to make a TH350c converter.
Some may not list it, but with a phone call I bet they oblidge.
It's just a 700r4 converter (30 spline) with a th350 pump hub.
The th350c is a great unit.
I am always collecting these cores because they're awesome for anybody up to around that 750hp mark that wants the simplicity of a 3 speed but some of the creature comforts of lockup.
Some may not list it, but with a phone call I bet they oblidge.
It's just a 700r4 converter (30 spline) with a th350 pump hub.
The th350c is a great unit.
I am always collecting these cores because they're awesome for anybody up to around that 750hp mark that wants the simplicity of a 3 speed but some of the creature comforts of lockup.
