Transplanting a TBI 350 in a Trans Am - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans Advertise
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 05-06-2014, 09:06 AM
Registered User
 
Join Date: May 2014
Posts: 7
Wiki Edits: 0

Thanks: 3
Thanked 0 Times in 0 Posts
Transplanting a TBI 350 in a Trans Am

Hi,

My 1980 Trans Am is running a 305 (non-turbo) linked to a TH350, where as my 1985 Chevy Van20 has a 350 (TBI) linked to a TH400.

What I intend doing is swapping the engines, along with the tranny, between the two cars however my concern is blowing up the ECU in the process. I don't want to do that.

Would appreciate any advice coming this way.

Best!
Attached Thumbnails
Click image for larger version

Name:	Trans Am Van.jpg
Views:	170
Size:	385.9 KB
ID:	143930  

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 05-06-2014, 10:28 AM
Registered User
 
Join Date: Apr 2007
Posts: 12,590
Wiki Edits: 0

Thanks: 220
Thanked 1,197 Times in 949 Posts
Quote:
Originally Posted by V8Junkie View Post
Hi,

My 1980 Trans Am is running a 305 (non-turbo) linked to a TH350, where as my 1985 Chevy Van20 has a 350 (TBI) linked to a TH400.

What I intend doing is swapping the engines, along with the tranny, between the two cars however my concern is blowing up the ECU in the process. I don't want to do that.

Would appreciate any advice coming this way.

Best!
I would give this a no vote. There's more involved than the computer that has to come over. All the wiring, fuel system, emissions, etc. The TBI is no gift except for the 350 short block. The heads are the accursed Swirl Ports meant to make torque for a truck not horsepower for a car. The TH400 is a beefsteak transmission in this case for a working truck. For a passenger car with a 350 SBC unless youíre building a competition level 350 this big TH400 isnít needed. The TH350 is a much better match for a 350 SBC. Not that this swap isn't doable but there's so much involved and in the end so much that's been compromised that I really think that you're money ahead to put a crate 350 into this and either rebuild the TH350 or better yet get your hands on a 700R4, stiffen up the rear axle ratio if its GM's ubiquitous 2.73 with something at least at 3.08 for cruising or steeper if you want a harder launch. Then you reap the benefits of the 700R4ís deeper low than the TH350 or 400 for getting away from stops, and you have the benefits of overdrive 4th and a lock up converter for cruising fast without burning a lot of fuel.

You can get a preview of what the swap youíre thinking of involves at the detail level from Mike Knellís book "Chevrolet TPI & TBI Engine Swapping". Iíd get a copy and read it before going further.

Bogie
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 05-06-2014, 02:20 PM
Registered User
 
Join Date: May 2014
Posts: 7
Wiki Edits: 0

Thanks: 3
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by oldbogie View Post
I would give this a no vote. There's more involved than the computer that has to come over. All the wiring, fuel system, emissions, etc. The TBI is no gift except for the 350 short block. The heads are the accursed Swirl Ports meant to make torque for a truck not horsepower for a car. The TH400 is a beefsteak transmission in this case for a working truck. For a passenger car with a 350 SBC unless youíre building a competition level 350 this big TH400 isnít needed. The TH350 is a much better match for a 350 SBC. Not that this swap isn't doable but there's so much involved and in the end so much that's been compromised that I really think that you're money ahead to put a crate 350 into this and either rebuild the TH350 or better yet get your hands on a 700R4, stiffen up the rear axle ratio if its GM's ubiquitous 2.73 with something at least at 3.08 for cruising or steeper if you want a harder launch. Then you reap the benefits of the 700R4ís deeper low than the TH350 or 400 for getting away from stops, and you have the benefits of overdrive 4th and a lock up converter for cruising fast without burning a lot of fuel.

You can get a preview of what the swap youíre thinking of involves at the detail level from Mike Knellís book "Chevrolet TPI & TBI Engine Swapping". Iíd get a copy and read it before going further.

Bogie

Thank you so much. I was thinking of all that and you're right... It's not really worth it. The thing is I;m in karachi, pakistan and we don't have crate motors at our disposal. PLus, What I have running in the Trans Am is a 305 and not a 350.

What do you think about my rebuilding the 305 and adding a mild cam to it?
Please share any other performance mods that might come to your mind.

On a different note, a lot of people are playing with 1UZ's and 1 and 2JZ-GTE's here. What would you say about throwing in one of these?
Just a thought.

Once again, thank you for taking the time out to reply to my post.
Appreciate it.
Reply With Quote Quick reply to this message
 
  #4 (permalink)  
Old 05-06-2014, 04:29 PM
Registered User
 
Join Date: Apr 2007
Posts: 12,590
Wiki Edits: 0

Thanks: 220
Thanked 1,197 Times in 949 Posts
Quote:
Originally Posted by V8Junkie View Post
Thank you so much. I was thinking of all that and you're right... It's not really worth it. The thing is I;m in karachi, pakistan and we don't have crate motors at our disposal. PLus, What I have running in the Trans Am is a 305 and not a 350.

What do you think about my rebuilding the 305 and adding a mild cam to it?
Please share any other performance mods that might come to your mind.

On a different note, a lot of people are playing with 1UZ's and 1 and 2JZ-GTE's here. What would you say about throwing in one of these?
Just a thought.

Once again, thank you for taking the time out to reply to my post.
Appreciate it.
Well that being in Karachi puts a different look on the problem. The TBI from the truck is transportable to the Firebird as is the TH400. But it is big electrical problem to deal with; that really takes being able to get your hands on the electrical system schematics for both vehicles to determine what comes out of the van and then goes into the Firebird.

Problem I always see with automatics is they age out with their engine and tend not to be happy for very long when a rebuilt or crate motor is bolted up to them. The TH400 is somewhat more resistant to this simply because it is more robust than the TH350 to start with and is overkill behind a 350 so it doesn't tend to wear out as quickly as the TH350 behind a SBC350.

You can always rebuild the 305 and it can take a larger cam with fewer problems than the TBI 350 since the 305 has a carb which is easier to tune for a larger cam than is the injection of the 350. Injection requires burning a new program onto a new PROM chip; this is a bit costly and doesn't always turn out correctly so given the length of your parts supply line that can be a difficult problem. What about the automatic are parts and expertise to rebuild this thing available?

Bogie
Reply With Quote Quick reply to this message
The Following User Says Thank You to BogiesAnnex1 For This Useful Post:
V8Junkie (05-08-2014)
  #5 (permalink)  
Old 05-06-2014, 04:50 PM
Banned
 
Join Date: Jun 2005
Location: St. Louis, MO
Age: 34
Posts: 9,527
Wiki Edits: 0

Thanks: 20
Thanked 405 Times in 378 Posts
Quote:
Originally Posted by V8Junkie View Post
Thank you so much. I was thinking of all that and you're right... It's not really worth it. The thing is I;m in karachi, pakistan and we don't have crate motors at our disposal. PLus, What I have running in the Trans Am is a 305 and not a 350.

What do you think about my rebuilding the 305 and adding a mild cam to it?
Please share any other performance mods that might come to your mind.

On a different note, a lot of people are playing with 1UZ's and 1 and 2JZ-GTE's here. What would you say about throwing in one of these?
Just a thought.

Once again, thank you for taking the time out to reply to my post.
Appreciate it.
If you can drop a 2jz-gte in it at a low cost then it is a NO BRAINER. That engine is still one of the best engines ever made.



Reply With Quote Quick reply to this message
The Following User Says Thank You to ap72 For This Useful Post:
V8Junkie (05-08-2014)
  #6 (permalink)  
Old 05-07-2014, 12:30 PM
Cars, Trucks, Boats
 
Join Date: Dec 2012
Location: Toledo, N.W.Ohio, USA
Age: 71
Posts: 6,338
Wiki Edits: 0

Thanks: 13
Thanked 772 Times in 726 Posts
. Yes, this swap would be way to much work, technical changes for too little benefit...

. Any recycling yards over there that you could pull a carb.'d 350 or 400 engine out of?

. Or, do a rebuild of the 305 with higher compression ratio pistons and a mild cam... what octane gas do you have available?
Reply With Quote Quick reply to this message
The Following User Says Thank You to BuzzLOL For This Useful Post:
V8Junkie (05-08-2014)
  #7 (permalink)  
Old 05-08-2014, 12:48 AM
Registered User
 
Join Date: May 2014
Posts: 7
Wiki Edits: 0

Thanks: 3
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by oldbogie View Post
Well that being in Karachi puts a different look on the problem. The TBI from the truck is transportable to the Firebird as is the TH400. But it is big electrical problem to deal with; that really takes being able to get your hands on the electrical system schematics for both vehicles to determine what comes out of the van and then goes into the Firebird.

Problem I always see with automatics is they age out with their engine and tend not to be happy for very long when a rebuilt or crate motor is bolted up to them. The TH400 is somewhat more resistant to this simply because it is more robust than the TH350 to start with and is overkill behind a 350 so it doesn't tend to wear out as quickly as the TH350 behind a SBC350.

You can always rebuild the 305 and it can take a larger cam with fewer problems than the TBI 350 since the 305 has a carb which is easier to tune for a larger cam than is the injection of the 350. Injection requires burning a new program onto a new PROM chip; this is a bit costly and doesn't always turn out correctly so given the length of your parts supply line that can be a difficult problem. What about the automatic are parts and expertise to rebuild this thing available?

Bogie
At this stage, rebuilding the 305 seems to be the way to go. I understand you would have gone this way. Procuring parts is always as issue but not the biggest one. I order mine online, from the states usually. Yes, the expertise to rebuild engines/transmission is available. I actually got my TH400 rebuild when i got the van.

The only reason American cars have become scarce is because of the gas prices and the ceiling on the age of the car that can be imported. No car over 3years old is permissible by law to import.

So, what would you recommend to improve the performance of the 305?
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 05-08-2014, 12:53 AM
Registered User
 
Join Date: May 2014
Posts: 7
Wiki Edits: 0

Thanks: 3
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by BuzzLOL View Post
. Yes, this swap would be way to much work, technical changes for too little benefit...

. Any recycling yards over there that you could pull a carb.'d 350 or 400 engine out of?

. Or, do a rebuild of the 305 with higher compression ratio pistons and a mild cam... what octane gas do you have available?

Hi,

I already have a carbed 305 hence won't really wanna go the 350 way unless it;s an absolute must. plus the upside of the 305 is economy. What combo would you suggest to go with on the 305 to retain economy and driving ease while improving the performance. Ok... more inclined towards the performance.

Thank you.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 05-08-2014, 12:54 AM
Registered User
 
Join Date: May 2014
Posts: 7
Wiki Edits: 0

Thanks: 3
Thanked 0 Times in 0 Posts
"what octane gas do you have available?"

We have Super Unleaded and High octane.
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 05-08-2014, 12:57 AM
Registered User
 
Join Date: May 2014
Posts: 7
Wiki Edits: 0

Thanks: 3
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by BuzzLOL View Post
. Yes, this swap would be way to much work, technical changes for too little benefit...

. Any recycling yards over there that you could pull a carb.'d 350 or 400 engine out of?

. Or, do a rebuild of the 305 with higher compression ratio pistons and a mild cam... what octane gas do you have available?
Quote:
Originally Posted by ap72 View Post
If you can drop a 2jz-gte in it at a low cost then it is a NO BRAINER. That engine is still one of the best engines ever made.
Thank you for writing in. No, it's going to cost pretty much the same but it's a newer engine hence, better on many levels, yet the simplicity of SBC's is simply overwhelming. Not to forget, the rumble of an american V8.

Reply With Quote Quick reply to this message

Tags
chevy 350, ecu, small block, tbi

Recent Engine posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Insurance
Please select your insurance company (Optional)

Log-in



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
350 TBI to 350 TBI VORTEC SWAP IWANTMOREHP Engine 8 10-20-2016 10:57 AM
Transplanting a TBI 350 in a 69 Chev PU fleetsidebob Engine 12 05-06-2014 08:58 PM
Transplanting a 85 Corvette 350/700R4 Poolplayer Electrical 6 01-27-2013 12:00 PM
350 tbi/trans problems allsouth88 Engine 3 02-21-2012 02:40 PM
need help to turn a 350 tbi into a rollerized 383 tbi Bradless Engine 2 01-03-2003 11:13 PM


All times are GMT -6. The time now is 11:06 AM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.