L29 tbi Unicorn?

[Wes-in-MC]

Sorry but this is a long one but hear me out. I have a '67 Chevelle that I want to get back on the road and drive. It has a 396 but its not the original engine. I want to put in a 454 with aftermarket fuel injection and an automatic. I've read countless forums about aftermarket efi systems and the pros and cons of each brand. The car is a factory 4-speed car but I want to run a automatic with overdrive for now and most of the aftermarket efi systems do not support od transmission control. I need this car to be very reliable because I plan on some cross county trips and I can't just pull into the local parts store and get a part for this heap. Driving to work one day, it dawned on me the solution.....I've been driving the answer to my problem for 25 years!! My daily is a '1995 k2500 with the L19 454. Other than the normal wear and tear items, a bad ignition control module is all that's ever giving me an issue with this engine.

I set out to find a 92-95 tbi 454/4l80e with all wiring and ECM to put in my Chevelle. This way I have modern-ish fuel injection with rock steady reliability and overdrive without spending a grand for just a transmission controller. So after many months of seeing ads on marketplace that were to far, to expensive and to worn out, I found a guy who was advertising a 1998 Vortec tbi engine and 4l80e. Wait - WHAT??? I saw the photo and it was a tbi so I thought the year was a typo. This thing had 22k miles out of a motor home and was about 3 hours away from me. I contact the guy and he sends me photos of the motor home, engine and speedo showing the mileage. I ask about the year and he tells me that the paperwork lists this pig as a '98 whatever brand motor home and he sends me a photo of the casting number on the block. Its a L29 Vortec with tbi.

So finally to the unicorn......I can't find any information on this setup. I didn't even know you could get a Gen6 454 with tbi and here I've lucked up and just bought one. I thought '96 up went multi port efi. I've read some about the L29 engine and it looks like I've bought a better, more powerful engine than I was looking for.

Before you folks rake me over the coals, I did try and search for L29 tbi and I didn't find anything but does anyone have any links to information on this thing?

Thanks for reading and sorry for it being so long!!

 

[someotherguy]

Motorhomes are often titled as the year they are built, doesn't mean that's what year the chassis/drivetrain was made. Last official year for a TBI 7.4 would have been 1995.

However! Checking up on that casting number, I found this: "10237297 Big Block V8 1996+ 454, 4 bolt, Vortec 7400, L-29 Generation VI"

So who knows? These guys found the same engine apparently: https://nastyz28.com/threads/gen-6-454-confusion.177566/

Sounds like you made a nice score on a low-mile engine/trans though!

Richard

 

[yevgenievich]

GM has industrial and medium duty lines that are different and often had old and new mixed together. Worth checking which heads it has, but it might have just been a tbi motor built with what was at the time current block.

 

[Schurkey]

Worth checking which heads it has

THOSE are the casting numbers that I want to see, along with the pushrod length (flat-tappet uses longer pushrods than roller-lifter.)

 

[L31MaxExpress]

GM kept TBI until 1998 in some applications on land. I have worked on a 97 427 TBI.

 

[L31MaxExpress]

Motorhomes are often titled as the year they are built, doesn't mean that's what year the chassis/drivetrain was made. Last official year for a TBI 7.4 would have been 1995.

However! Checking up on that casting number, I found this: "10237297 Big Block V8 1996+ 454, 4 bolt, Vortec 7400, L-29 Generation VI"

So who knows? These guys found the same engine apparently: https://nastyz28.com/threads/gen-6-454-confusion.177566/

Sounds like you made a nice score on a low-mile engine/trans though!

Richard

The old G-vans had TBI through 96 model year. Engine options were a 4.3, 350 and 454 as well as the non-turbo 6.5. Commercial P-series chassis had it through 98. Mexico had it until 98 as well. TBI L31 and L29 were on the power team combinations in GM Heritage information in the 97 model year information I looked at. The 350 made 230 hp and 320 tq, I forget what the L29 made but it was more than the basic L19 as well.

 

[454cid]

I have no direct expereince, but I've read that the late TBI engines were built with the new Gen VI block castings.

You didn't get the fuel injection system, or you removed it already?

 

[454cid]

GM kept TBI until 1998 in some applications on land. I have worked on a 97 427 TBI.

Tall deck engine out of a box truck?

 

[L31MaxExpress]

Tall deck engine out of a box truck?

Schoolie, school bus converted to a RV. Had the tall deck 427 TBI and an Allison 4spd.

 

[L31MaxExpress]

When the 427 died, the bus got an 8.0L as a replacement and I tuned the chip to run the 8.0L. I tried to talk him into the L29 intake manifold with spacers and a E38 or E40, but he wanted the simplicity of the TBI. The 8.0L has a 58x/4x crank and cam sensor out of the box, hence the GMPP big block 58x conversion setup.