Author Topic: Looking for suggestions on L29 install  (Read 455 times)

Offline boomboy110

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Looking for suggestions on L29 install
« on: February 12, 2018, 11:08:29 PM »
Hello everyone! This is my first post on this board. I have looked through many of the posts/topics. You guys are full of information, and I appreciate all your knowledge. I have done many searches looking for info, and find bits and pieces. But, haven't found anyone that has done the exact transplant that I am looking into. Sorry, if I missed it somewhere. Just looking for the right direction.
I have a '79 C10 LB. Currently, it has a 350 with a th350. I have already purchased($400) an L29 out of a '99 Chevy 2500. It has the complete motor, fuel/intake system, and PCM. I'm already planning on having the motor refreshed, and have a different cam installed. Shooting to get 500+ hp, and guessing 600+ tq.
First question, I'm undecided if it is worth adapting the truck to the MPFI that the l29 currently has, install an aftermarket EFI system(to keep the nostalgic Carb appeal), or convert it to Carb. I am trying to make it a custom/show truck, but appreciate the old school look under the hood, and don't know if I like the look of the MPFI intake. Any suggestions for ease and best bang for buck on the fuel system?
Next question is, in regards to the transmission. I currently have a TH350, which is just stock. Should I have that one rebuilt with upgraded parts, buy one already setup with upgrades(ei-Monster transmission), or convert it to a completely different transmission?
Last question, for now.  ;D - The rear end, it currently has an open 3.08 diff. What would you recommend for gears, and I assume it goes without saying that i need to throw a LSD in? I realize, my choice in transmission will have affect on what gears to run. As I said, I will have it mainly as a show truck/toy. No plans of taking to the track, but would like to be able to get on highway at times without my RPM'S screaming at 60 mph.
I know that some of my questions might be very newbie sounding. But, I have actually lived in a garage for a good 20+ years of my life. I just don't have much experience with converting from carb to EFI. And, this will be my first ever BBC. I'm pretty excited, and at this point I am just trying to do all my research, so when the time comes, I have a good grasp and what I need to do for work involved, and $ involved.

Offline Rapid Roy

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Re: Looking for suggestions on L29 install
« Reply #1 on: February 13, 2018, 06:15:10 AM »
Welcome
1974 Cheyenne 10 LWB 350/TH350/AC/4 BBL Quadrajet

Offline Irish_Alley

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Re: Looking for suggestions on L29 install
« Reply #2 on: February 13, 2018, 03:34:39 PM »
if its possible i would try and find what trans came behind that l29. if you have the ecm for it already i should be set up for that trans. that way you get to keep OD
If you canít tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline boomboy110

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Re: Looking for suggestions on L29 install
« Reply #3 on: February 15, 2018, 03:25:54 PM »
thanks for the Welcome.
Irish- I am not 100% sure, but I think that it was a 4l80e behind the l29. And that is a thought that I had. Although, the transmission was previously sold before me purchasing the engine. But, it was out of a k2500, so it was a 4wd trans, and I have the c10. I have looked into the 4l80e's with that thought in mind. What would I do for a shifter though? It is currently a 3speed on the column. I am pretty sure that the 4l80e would be an electronic shift vs the mechanical linkages. So, would I just switch it to a floor shifter, like my thoughts of doing so regardless are anyways?

Offline Irish_Alley

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Re: Looking for suggestions on L29 install
« Reply #4 on: February 15, 2018, 03:32:42 PM »
im not going to even try to answer about the shifter. my 91 has just a 4 gear shifter (7 position- P,R,N,OD,3,2,1) the same you would use for the 700r4 but i think the 4l80e changed how they shifted like around 98 or something
« Last Edit: February 15, 2018, 03:34:26 PM by Irish_Alley »
If you canít tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline boomboy110

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Re: Looking for suggestions on L29 install
« Reply #5 on: February 15, 2018, 03:42:52 PM »
Thanks for your advice Irish. I'm not real sure either. hopefully, someone will chime in and help me some. Or point me in direction of someone that may have done what I am looking to do. I think think that they changed it to electronic shift as well. Which, would probably make the floor shifter install more justifiable, and maybe even easier.

Offline Irish_Alley

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Re: Looking for suggestions on L29 install
« Reply #6 on: February 15, 2018, 06:59:10 PM »
for some reason 98 is sticking in my head about the year for electric shifter box thingy on the side of the 4l80e
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Offline 1967KaiserM715

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Re: Looking for suggestions on L29 install
« Reply #7 on: February 15, 2018, 08:43:17 PM »
for some reason 98 is sticking in my head about the year for electric shifter box thingy on the side of the 4l80e
'95 went to the cable shift, and the neutral safety backup up switch mounted to the side of the transmission.(your electric shifty box thing)

'91-'93 had minor differences in electronics and the valvebody, but can be changed to be used with '94+ ecu. Your ideal transmission would be the '94, it still operated under mechanical linkage, so the linkage for your th350 could be made to work.(might not have the ability to choose gear 1, as you have positions for OD, D, 2, and 1. The th350 would have only D,2,1)

You could still use any '94+ 4l80e if you swap the shift shaft, it does require dropping pan, and changing one or two seals.

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Current Vehicles:1985 GMC K10(Daily)
1975 Beetle(not running) 1985 Mercedes 300D(not running) 1952 M35    1967 M715(not running)
1991 GMC K2500(under repair)

Offline Irish_Alley

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Re: Looking for suggestions on L29 install
« Reply #8 on: February 15, 2018, 08:47:52 PM »
good to know. i have a 4l80e out of a 99 or 98 that needs to be rebuilt anyway and i thought it was useless to me since it had that black box on it
If you canít tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes