few Q's about 700R4 to TH350 Swap
Thread Starter
Supreme Member
iTrader: (1)
Joined: Jun 2004
Posts: 1,663
Likes: 0
From: Menominee MI
few Q's about 700R4 to TH350 Swap
at first i wasn't even interested in this swap what so ever, but now i'm startin to consider it, but I got a few questions about it....First thing, if i swap this in, what is my gas mileage gonna do??? severely drop?? i don't do a lot of highway driving, but I do get her on the highway when its time to cool her off, it gets a bit hot....also will i see a performance gain at all? or is the TH350 pretty much just a 700R4 with one less gear??? also how much HP can a TH350 handle?? even anybody has any more positive or negative input on the swap, feel free to post, im open to any suggestions..
Do a search. The TH350 is stronger than the 700R4 in stock form, but either could be built to handle alot of power. The stock 700R4 in my IROC fried and I'm running a TH350 now. My mileage did go down, but I'm happy with the trans. It can take a beating. If you really need the 4th gear then consider a TH400. I just wanted the cheapest strong replacement so I ended up with a fresh rebuilt TH350 for $275.
Originally posted by CrazyHawaiian
Do a search. The TH350 is stronger than the 700R4 in stock form, but either could be built to handle alot of power. The stock 700R4 in my IROC fried and I'm running a TH350 now. My mileage did go down, but I'm happy with the trans. It can take a beating. If you really need the 4th gear then consider a TH400. I just wanted the cheapest strong replacement so I ended up with a fresh rebuilt TH350 for $275.
Do a search. The TH350 is stronger than the 700R4 in stock form, but either could be built to handle alot of power. The stock 700R4 in my IROC fried and I'm running a TH350 now. My mileage did go down, but I'm happy with the trans. It can take a beating. If you really need the 4th gear then consider a TH400. I just wanted the cheapest strong replacement so I ended up with a fresh rebuilt TH350 for $275.
Senior Member
Joined: Dec 2003
Posts: 647
Likes: 0
From: Oklahoma
Car: 1991 Trans AM GTA
Engine: 5.7L TPI
Transmission: 700R4
I am also considering doing this swap myself and would like some info on it. My 700r4 is starting to slip on me and I have considered the swap to the TH350.
Supreme Member
iTrader: (1)
Joined: Apr 2002
Posts: 4,671
Likes: 1
From: Waterloo, Iowa
Car: 86 firebird with 98 firebird interi
Engine: pump gas 427sbc Dart Lil M 13.5:1
Transmission: Oldani TH400 w/ BTE 9" convertor
Axle/Gears: 31 spline Moser/full spool/4.11Rich
There are far too many posts on here dealing with this issue, hate to say search, but you will be overwhelmed when you do, I promise
When I did the swap 700r4 with 2800 stall to a TH350 with 3500 stall, absolutely NO difference in ET/mph. Less mpg since you dont have OD. Ability to build a stronger tranny cheaper and have it done at any shop in the country-much harder finding guys that really know what they're doing on an OD tranny.
I happen to have a TH350 long tail with only 1 season on it with the TCI 3500 stall 4 sale. Very consistent tranny all year long when I looked back at old timeslips. Use your stock 700r4 driveshaft, need to get the torque arm mount and dipstick-used that on my TH400. PM me if interested
When I did the swap 700r4 with 2800 stall to a TH350 with 3500 stall, absolutely NO difference in ET/mph. Less mpg since you dont have OD. Ability to build a stronger tranny cheaper and have it done at any shop in the country-much harder finding guys that really know what they're doing on an OD tranny.
I happen to have a TH350 long tail with only 1 season on it with the TCI 3500 stall 4 sale. Very consistent tranny all year long when I looked back at old timeslips. Use your stock 700r4 driveshaft, need to get the torque arm mount and dipstick-used that on my TH400. PM me if interested
Trending Topics
Senior Member
Joined: Dec 2003
Posts: 647
Likes: 0
From: Oklahoma
Car: 1991 Trans AM GTA
Engine: 5.7L TPI
Transmission: 700R4
IHI...thanks for the info. I found this thread through a search and yes there is an overwhelming amount of info on the 700 to 350 conversion/swap.
Also...you have a PM.
Also...you have a PM.
Originally posted by klumb15
where did you get it for 600 bucks with TC and assembled???
where did you get it for 600 bucks with TC and assembled???
Originally posted by CrazyHawaiian
Damn I sure feel retarded now. Man, I cant understand this, I went for a ride with a friend that runs a TH400 and I swear he had OD. Am I going Crazy?? hahaha
Damn I sure feel retarded now. Man, I cant understand this, I went for a ride with a friend that runs a TH400 and I swear he had OD. Am I going Crazy?? hahaha
Thread
Thread Starter
Forum
Replies
Last Post
C409
Engine/Drivetrain/Suspension Parts for Sale
1
Sep 1, 2015 03:42 PM








