LT1 Manifold/GenI Block Conversion Checklist
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Staging Lane
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From: Columbia, Missouri
LT1 Manifold/GenI Block Conversion Checklist Hi guys. This is my first post, as a new member, but I am very familiar with forums and such. I've read around a lot and am very happy with what I've found. I have an interesting project that I think needs some input from people experienced with LT1 fuel injection. Pics included.
Here's the car:
1977 Chevrolet Corvette
Here's the engine:
1973 SBC 400 +.020
1989 SBC 14102193 heads
Full roller retrofit w/ LT4 Hot Cam
Complete Z28 serpentine belt system
Here's the transmission:
TH200R4 - Multi fit case
Here'e the intake:
1994 Impala SS LT1 intake/harness/computer
Here's a list of what I'm doing, and pics of progress follow. I have a link to guy that will machine my manifold to work with my Gen1 block. I'll be able to use a small cap HEI, and ditch the EGR crap. The harness and computer are being sent of as well.
The harness will be modified to work with my car, and set up for my engine choice. All un-needed connections will be deleted, and needed ones will be added.
I'm buying a re-worked 52mm throttle body with bearings installed, and a nice polished finish.
The chip will be re-programmed for the 400, as well as altered for deleted things like VATS, EGR, and trans control.
I know I will have to get a TPI/LT1 external fuel pump, but know nothing of the fuel rail system and how the regulator will work with an aftermarket pump. My car does have a return line, so I'm set there. I wonder what LT1s had fuel rails where the lines exit on the left instead of the right.
I'm looking for suggestions, helpful comments, pictures of similar setups, and links to sites with valuable info. Thanks for any help guys. Great to be a new member.
Here's a few pics.
I installed a manifold and carb before switching to LT1 intake.
Here's the car:
1977 Chevrolet Corvette
Here's the engine:
1973 SBC 400 +.020
1989 SBC 14102193 heads
Full roller retrofit w/ LT4 Hot Cam
Complete Z28 serpentine belt system
Here's the transmission:
TH200R4 - Multi fit case
Here'e the intake:
1994 Impala SS LT1 intake/harness/computer
Here's a list of what I'm doing, and pics of progress follow. I have a link to guy that will machine my manifold to work with my Gen1 block. I'll be able to use a small cap HEI, and ditch the EGR crap. The harness and computer are being sent of as well.
The harness will be modified to work with my car, and set up for my engine choice. All un-needed connections will be deleted, and needed ones will be added.
I'm buying a re-worked 52mm throttle body with bearings installed, and a nice polished finish.
The chip will be re-programmed for the 400, as well as altered for deleted things like VATS, EGR, and trans control.
I know I will have to get a TPI/LT1 external fuel pump, but know nothing of the fuel rail system and how the regulator will work with an aftermarket pump. My car does have a return line, so I'm set there. I wonder what LT1s had fuel rails where the lines exit on the left instead of the right.
I'm looking for suggestions, helpful comments, pictures of similar setups, and links to sites with valuable info. Thanks for any help guys. Great to be a new member.
Here's a few pics.
I installed a manifold and carb before switching to LT1 intake.
I believe corvettes had the fuel lines go off to the passenger side. Early years the lt1 intake did not have a crossover in front, that was the later years for the LT1. I am sure someone with better info on this subject will chime in.
Good luck with the project.
Good luck with the project.
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From: POULSBO WA.
How are you going to use the lt1 intake on a gen 1 block, there are no water passages, correct me if I am wrong but dont those heads have water passages that need to surculate through the intake manifold? the LT1 heads and manifold have no water passages, no water goes through the intake.
Thread Starter
Staging Lane
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From: Columbia, Missouri
Originally Posted by UA-Plumber
Yep, that's the site that's doing the conversion for me. He's behind schedule right now but I will be sending it to him in a week or so.
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Staging Lane
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From: Columbia, Missouri
Originally Posted by thesoundandthefury
What kind've PCM/wiring harness are you using with this setup? An LT1 PCM can't control the injectors unless it gets a signal from an optispark.
The guy converting my harness and computer says it's no big deal switching to OBD1 and HEI distributors. I explained what I had, '93 harness and computer, and he was very familiar with them and was 100% confident. I trust him on that.
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Staging Lane
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From: Columbia, Missouri
Originally Posted by daniel6718
lt1 intake is restrictive on an lt1, even more on a big motor...
I'm not a high RPM kind of driver. I like low end torque. I'm using a 52mm throttle body, and am told the manifold is already set up for that bore. I'm looking into porting and polishing the manifold, but several sources have led me to believe that it won't make a big enough difference to be worth it.
Many LT1 guys spend alot of money so they can run a carb intake on their LT1, I wouldnt pay extra to run an LT1 intake on one...
Im sure you could find a regular intake that fit your needs and performed better, unless its the cheap EFI that you want to utilize.
Im sure you could find a regular intake that fit your needs and performed better, unless its the cheap EFI that you want to utilize.
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Staging Lane
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From: Columbia, Missouri
Originally Posted by Valkyn
Many LT1 guys spend alot of money so they can run a carb intake on their LT1, I wouldnt pay extra to run an LT1 intake on one...
Im sure you could find a regular intake that fit your needs and performed better, unless its the cheap EFI that you want to utilize.
Im sure you could find a regular intake that fit your needs and performed better, unless its the cheap EFI that you want to utilize.
You hit the nail on the head. I want to build an EFI motor. I've built lots of carbed motors, and as you can see from the pics...this 405 used to have a carb on it. I have just decided to switch to EFI, and the easiest and cheapest, with good results, is LT1.
Originally Posted by Durango_Boy
The guy converting my harness and computer says it's no big deal switching to OBD1 and HEI distributors. I explained what I had, '93 harness and computer, and he was very familiar with them and was 100% confident. I trust him on that.
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Staging Lane
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From: Columbia, Missouri
Originally Posted by thesoundandthefury
Okay, what did he suggest you use for a cam position sensor if not the optispark?
I think he was deleting both cam position and crank position sensors. I did not ask in great detail...he just said my combo would work great when it's all finished.
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From: Decatur, TN (N-W of Athens)
Wasn't aware you could delete them from the computer... I think for your setup, you'll be wanting to run a TPI computer. Since basically what youre running is a TPI setup with a TPIS intake. Which is just a LT1 clone intake for TPI cars with distributor hole and so forth. I think you're spending more money than you need to by using LT1 setup.
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Staging Lane
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From: Columbia, Missouri
Originally Posted by Formula350
Wasn't aware you could delete them from the computer... I think for your setup, you'll be wanting to run a TPI computer. Since basically what youre running is a TPI setup with a TPIS intake. Which is just a LT1 clone intake for TPI cars with distributor hole and so forth. I think you're spending more money than you need to by using LT1 setup.
I looked into it, but I already had the harness and computer. I'd have to have the chip custom programmed anyway because of the engine's size. The program cost is the same no matter what I start with. The harness for a TPI computer would have cost extra on top of the one I have, and it would have to be altered to fit my car and engine as well. I ran it up both ways. I considered a lot of options and found this to be the just fine for what I needed.
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From: Decatur, TN (N-W of Athens)
So a LT1 harness is a direct bolt on for your old vette? 
I would've thought either harness would've had to be modified.
I just a bit more on your initial post. I believe my 93 F-Body lines hook up on the left. I don't have the front cross over.
I would've thought either harness would've had to be modified.I just a bit more on your initial post. I believe my 93 F-Body lines hook up on the left. I don't have the front cross over.
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Staging Lane
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From: Columbia, Missouri
Originally Posted by Formula350
So a LT1 harness is a direct bolt on for your old vette? I would've thought either harness would've had to be modified.
I just a bit more on your initial post. I believe my 93 F-Body lines hook up on the left. I don't have the front cross over.
I would've thought either harness would've had to be modified.I just a bit more on your initial post. I believe my 93 F-Body lines hook up on the left. I don't have the front cross over.
No, the LT1 harness is not a direct bolt on, but neither is the TPI harness. Both would have to modified. Same with the computer. That's why I went with the ones I had.
As far as the fuel rails...do they exit on the driver's side or passenger side? The fuel lines are on the passenger side of my Vette so I need to find fuel rails that exit over there.