Replacing Muncie with a TH350
Thread Starter
Instructor
Joined: Jun 2006
Posts: 105
Likes: 0
From: central Texas
Replacing Muncie with a TH350
I have a 72 with a 383 stroker. The stock 4 speed shifter is in need of replacement and I have an 871 blower I plan on installing soon. I also have a race prepped TH350 in the garage that was going in my kid's Nova but isn't needed now. Question is... I know I'll need a torque converter (already have a flex plate), I have the tranny, the yokes are the same it appears? I have a used auto crossmember. Will need a shifter (anyone put an aftermarket shifter in with an automatic or better off to buy replacement stock shifter - I like the look of the T handle shifters of the 70s like the B&Ms)? I am thinking the stock shift boot will slip over the auto shifter without changing the console trim. Cable to connect shifter and tranny kickdown. Some sort of tranny cooler since the radiator doesn't have fittings. I am thinking I can leave the clutch pedal in and use a spring to hold it out. Am I overlooking anything else?
Thanks,
Dennis
Thanks,
Dennis
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
Originally Posted by Scooter_boy
Am I overlooking anything else?
Thanks,
Dennis
Thanks,
Dennis
Thread Starter
Instructor
Joined: Jun 2006
Posts: 105
Likes: 0
From: central Texas
650hp and drivetrain longivity?
Figured I'd end up switching to the auto sooner or later anyway. The 383 makes about 450 hp but running a dual carb 871 blower on it should get it up near 650 or so and I figured with my foot, I'd end up damaging drivetrain components. My thinking is the auto will be a little easier on everything else. You're right though, it's a wash money wise and the 4 speed is a hoot... shoot I'm going through TA Radials in 5,000 miles or so since I swapped in the 383 and with the blower, I'll end up running stickier tires. I have all of the original parts to put back if I ever decide to sell the car but I always wanted a car with a motor that is taller than the roof and that's what I am building... Loud *** Hooker sidepipes and all! Right now resale value isn't really an issue.
Drifting
Joined: Jul 2004
Posts: 1,695
Likes: 65
From: Kissimmee fl
Finalist 2021 C3 of the Year - Modified
2017 C3 of Year Finalist
Cruise-In VIII Veteran
St. Jude Donor '07
I could be wrong but I think the cross member on the 72 is welded in, Unless you plan on cutting it out you will not need the other one. My car was converted from a 4 speed to 350 auto before I got it. The original welded in cross member was not molested. You are correct the 4 speed upper boot will work with the auto shifter but you will need to trim the shifter hole in the floor to fit it in. Also make sure you install the lower shifter seal to keep hot air out of the cabin. With out the bolt in cross member you will need to drop the exhaust to get the tranny in. Side pipes cure that. 
Not sure about anything but the stock shifter. I do have an extra one of those lying around if you are interested. PM me.
Not sure about anything but the stock shifter. I do have an extra one of those lying around if you are interested. PM me.
Race Director
Joined: Jun 2005
Posts: 10,189
Likes: 206
2018 Corvette of Year Finalist
2017 C3 of Year
I'm going the opposite way, and replacing a Th350 with a M21, I have the trans out and now looking for the 4 speed, and would be interested in your's if possible. Along with the shifter, linkage, flywheel, etc. Let me know if we can work something out. Oh and fill out your profile it helps
WB
WB
Thread Starter
Instructor
Joined: Jun 2006
Posts: 105
Likes: 0
From: central Texas
c69vette and War Bonnet
c69, got the pm - thought I replied - never used the board before or pm's either. I need to check on the rest of what I need and I'll get back to you soon.
War Bonnet, not sure I want to part with the stock parts. I still have the #s matching engine and just figured I'd put the trans next to it in the garage incase I ever decide to sell the car down the road. Shoot, I even saved the stinkin' exhaust from underneath it. That would make the swap a lot easier for both of us though........
War Bonnet, not sure I want to part with the stock parts. I still have the #s matching engine and just figured I'd put the trans next to it in the garage incase I ever decide to sell the car down the road. Shoot, I even saved the stinkin' exhaust from underneath it. That would make the swap a lot easier for both of us though........
Drifting
Joined: Aug 2004
Posts: 1,677
Likes: 1
From: Potomac Falls VA
Where are you located? I have a TH400 which runs very strong with a almost new torque converter and flywheel which was just put on January of this year when I had the engine put in. I am swapping in a 5 spd manual from Tremec.
I would let all of this go very reasonably...
I would let all of this go very reasonably...
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
NCM Grand Opening Veteran
Joined: Sep 2005
Posts: 20,979
Likes: 384
From: South of giving a damn
St. Jude Donor '11, '17
Here's what I would do: Do a nice, stock rebuild on the 72's original engine & put it back in. Sell the 72 for large dollars (or keep it, depending on your finances), buy a 78 or 79 (which will come with an auto), drop the blown engine in this car & everything is already setup for a TH350 or TH400. You will not negatively affect the price of a 78 or 79 with these mods & the running gear is the same as the earlier cars.
Thread Starter
Instructor
Joined: Jun 2006
Posts: 105
Likes: 0
From: central Texas
changed my mind
well I changed my mind... I bought a Hurst Competition Plus shifter to replace the stock one so that'll fix my shifter issues. Plan on driving it til Christmas and then pulling the headers and sending them to be jet hot coated. While they are out, I'll bolt on the blower (If my wife buys me the carbs I want) and put it all back together. We'll see how long the tranny lasts and have all kinds of fun til then.........
Drifting
Joined: Dec 2004
Posts: 1,345
Likes: 3
Originally Posted by Scooter_boy
well I changed my mind... I bought a Hurst Competition Plus shifter to replace the stock one so that'll fix my shifter issues. Plan on driving it til Christmas and then pulling the headers and sending them to be jet hot coated. While they are out, I'll bolt on the blower (If my wife buys me the carbs I want) and put it all back together. We'll see how long the tranny lasts and have all kinds of fun til then.........
I have always (40 years, I'm 51) thought is was SAD to even SEE an automatic Corvette. The thought of converting a 4-speed to an auto was horrifying!!!
Instructor
Joined: May 2006
Posts: 206
Likes: 0
From: Barrie Ontario
Shane
I'm in Ontario, Canada, are you interested in selling. I presume its a 4 speed automatic. I have a 350 with a 350 auto, the motor is re-bored 10%over with a performance cam and extended lifters, etc. not sure what hp, but certainly has a punch..
Please advise, Thanks
Domer.
I'm in Ontario, Canada, are you interested in selling. I presume its a 4 speed automatic. I have a 350 with a 350 auto, the motor is re-bored 10%over with a performance cam and extended lifters, etc. not sure what hp, but certainly has a punch..
Please advise, Thanks
Domer.
