[CFster]

Hi, we have a '67 GTO with the stock 400 and a 4L60E we installed a few years ago. Now we want to put an LS3 in it.

I've done a bunch of research, and have picked most of my parts. However, there's a few things I'm not entirely clear on. I've scoured many threads on Chevelles, and some GTOs (but mostly different years than mine). I know there are differences...

1. I'm intending on running the stock gas tank, with an external Walbro fuel pump and filter/regulator. Do I need to run some sort of evap system? Purge or vent solenoid? Evap or charcoal canister? Doesn't the LS3 have provisions for this (evap line coming off the motor)? I know the LS3 harness has pinouts for those items.

2. What is the benefit of going with a SpearTech harness rather than the GMPP harness? Are either of these programmable?

3. Will the stock manifolds that come with an LS3 crate motor work in a '67 A-Body? I'm guessing not!

4. If not, how do the Edelbrock short headers compare to the stock manifolds performance wise? I really don't want full length headers and I'm aware there's a power trade off. What other options are there for short or mid length headers or manifolds?

5. I want to keep from moving my transmission at all. Which mounts will put my motor in the stock location? My understanding is the Dingo Sliders position the engine 1/4" higher than stock, Edelbrock's move the engine 3/8" forward from stock and the BRP mounts require you to drill holes in the frame. By stock location, I assume these manufacturers are talking about the rear mounting face of the block right? I mean what else can they use for reference?

6. Am I required to run a smaller alternator than comes with the Corvette accessory drive kit to avoid hitting the inner tie rod linkage? I'm already planning on a Kwik A/C bracket as I have a Vintage Air System in it already.

7. I'm planning on using AutoKraft oil pan but have heard that combination with a 4L60E and headers makes the starter virtually impossible to get at due to the pan's kick outs at the bottom. Any other options I should be looking at?

Thanks and I'll be sure to post plenty of pics of the build once we get going.

-Colin

[andrewb70]

Originally Posted by CFster

Hi, we have a '67 GTO with the stock 400 and a 4L60E we installed a few years ago. Now we want to put an LS3 in it.

I've done a bunch of research, and have picked most of my parts. However, there's a few things I'm not entirely clear on. I've scoured many threads on Chevelles, and some GTOs (but mostly different years than mine). I know there are differences...

1. I'm intending on running the stock gas tank, with an external Walbro fuel pump and filter/regulator. Do I need to run some sort of evap system? Purge or vent solenoid? Evap or charcoal canister? Doesn't the LS3 have provisions for this (evap line coming off the motor)? I know the LS3 harness has pinouts for those items.

2. What is the benefit of going with a SpearTech harness rather than the GMPP harness? Are either of these programmable?

3. Will the stock manifolds that come with an LS3 crate motor work in a '67 A-Body? I'm guessing not!

4. If not, how do the Edelbrock short headers compare to the stock manifolds performance wise? I really don't want full length headers and I'm aware there's a power trade off. What other options are there for short or mid length headers or manifolds?

5. I want to keep from moving my transmission at all. Which mounts will put my motor in the stock location? My understanding is the Dingo Sliders position the engine 1/4" higher than stock, Edelbrock's move the engine 3/8" forward from stock and the BRP mounts require you to drill holes in the frame. By stock location, I assume these manufacturers are talking about the rear mounting face of the block right? I mean what else can they use for reference?

6. Am I required to run a smaller alternator than comes with the Corvette accessory drive kit to avoid hitting the inner tie rod linkage? I'm already planning on a Kwik A/C bracket as I have a Vintage Air System in it already.

7. I'm planning on using AutoKraft oil pan but have heard that combination with a 4L60E and headers makes the starter virtually impossible to get at due to the pan's kick outs at the bottom. Any other options I should be looking at?

Thanks and I'll be sure to post plenty of pics of the build once we get going.

-Colin

Hi Colin,

Let me give this a stab.

1. I would encourage you to run an intank pump, for a number of reasons that I don't want to list here. Check out the Spectra Premium EFI tanks. They can be sourced from RockAuto for under $400 with a suitable fuel pump. EVAP and all that can be eliminated.

2. The GMPP harness is for a manual trans only. If you want a computer controlled trans, go with Speartech.

3. No.

4. I am not aware of any midlength header options. The Edelbrock longtubes are priced right and offer good ground clearance.

5. When I swapped from a BBC to an LS I used the Edelbrock mounts. The trans remained in exactly the same position. Not sure what will happen compared to the Pontiac engine, but if I was a betting man, I would stay it will stay in the same place.

6. The Corvette accessory drive mounts the alternator up high on the drivers side. No issues with clearance. The power steering pulley will get close to the steering box but should not pose any issues.

7. Bart had an issue with this and I don;t have a solution. I do believe that Holley will be showing a cast pan at SEMA that is designed for swaps.

Good luck.

Andrew

[Donovan]

3. Try looking at a set of full size truck manifolds, Trailblazer SS manifolds or 2010 Camaro manifolds. They are all rear dump and may work. You'll have to find out. Luckily they can all be bought cheap sometime free if you look around. Check ebay for pics to compare.

Of the three I'd say the fullsize truck ones are the most performance oriented. They have large volume runners and fully 2.5" diameter collectors. The others are a little over 2" on average.

The LS3 manifolds are center dump, so they hit all kinds of stuff in the older car frame/chassis

[Ollie]

1:Modify the stock tank, using a LS1 fuel pump module.The 99-02 Firebird, Camaro fuel pump is a module design inside a bucket that keeps the fuel pump covered with fuel even when the fuel is low. This is the set up I am using on my 79 TA. The bucket is spring loaded and will compress from 10 1/2 inches to 9 1/2 inches to compensate for different depths of the tank.

I bought the fuel pump module, the mounting adapter and the fuel line adapters from the Vettworks. The fuel line adapters are Russell pn 640850. They are 3/8 inch to #6 AN line. Summit lists them.
http://www.vetteworksonline.com/ls1_conversion_fuel.htm

This is another link showing the module installation in a Vega gas thank.
http://forums.h-body.org/viewtopic.p...+tank&start=30

This post has link sources for clamps hoses wiring and and after market pumps.
http://www.pro-touring.com/forum/sho...ng-a-fuel-tank

Ls1 Tech has a Fueling-Injection forum with good technical advice at this link.
http://www.ls1tech.com/forums/fueling-injection-8/

This link is to a post by takid455, showing how He mounted the fuel pump module and retained the original fuel sender.
http://www.pro-touring.com/forum/sho...#37;2874-77%29

[CFster]

Originally Posted by Donovan

3. Try looking at a set of full size truck manifolds, Trailblazer SS manifolds or 2010 Camaro manifolds.

Thanks I'll look into it. I also just found out Street & Performance has shorty headers. I just want to avoid any clearance issues underneath with full length headers.


And thanks Ollie for all the info. I'm going to have some reading for this evening!

[Ollie]

There is some good info in those links. don't forget to bookmark everything.
Read the stickeys at the top of the fueling and Injection forums at LS1 Tech.

[68gtoMN]

What about consulting Bman's thread on his 64 conversion?

[b-man]

Originally Posted by 68gtoMN

What about consulting Bman's thread on his 64 conversion?

It's a lot of reading, but most of your questions will be answered in there.

[CFster]

Getting ready to pull the trigger on this project:

I have a 4L60E with a non removable bell housing. It's an earlier style, so it will only bolt up with five bolts instead of six. I hope that will be sufficient.

Can anybody verify my part numbers for the flexplate and spacer that I need?

12602448 - Flexplate
12563532 - Spacer

And here's my parts list:

19244097 - LS3 Crate Engine (btw, the GMPP catalog says this engine comes installed with a 2009 throttle body and I should use a 2008 throttle body if I'm using the GM harness, what's up with that?)
19155067 - Corvette Accessory Kit (Pace makes their own kit with is basically the same kit minus the compressor and brackets for $120 less - I'll have to investigate)
K10143 - Kwik Sanden Compressor Mount (up high) for my existing Vintage Air kit.
12635649 - Damper
AutoKraft - Oil Pan
Edelbrock - Mounts
SpearTech - Manual Transmission Harness Kit with ECU
SpearTech - O2 and MAF sensors
Street & Performance - Shorty Headers
Walbro External Pump 255lph
Filter/Regulator NAPA 373 (Corvette style)

As mentioned above, I'm already running a 4L60E with a Compushift controller. I've decided to keep that controller and go with a manual harness - one reason being I'd like to install a Shrifter and it requires the Compushift.

I've also been running a Griffin radiator with a big Spal puller fan. I hope that will be sufficient.

The rest of the parts will be had during the install - lines, fittings, ductwork etc.

[b-man]

Concerning the flexplate and spacer, you might find an answer by looking through these different flywheel and spacer parts listings:

http://www.crateenginedepot.com/Pres...lates-C19.aspx

http://www.bulkpart.com/Merchant2/me...ory_Code=FLYgm

I had to remove the original Corvette-only flexplate and replace it with a 'conventional' one, the GM part # is there somewhere in my Tempest build thread. Not sure if your 4L60E can use the same flexplate as my 4L70E, if so there's no need for a spacer. My undestanding was the spacer would only be needed if a TH400 or TH350 trans was going to be used, but I'm not 100% sure.

[drailed]

I just picked up the Pace non AC accessory kit for my 67. I think I paid $500 and something for it. They renumber everything with there own part numbers I believe. You may want to consult with John over at Speartech on your harness and TB. Hes very helpful.

[gearbanger]

Man, that is a nice GTO.

[CFster]

A few pics.

[drailed]

Any updates??

[CFster]

Sorry, it's been a long winter.

Got the motor and radiator in, transmission cooler plumbed (external cooler on the frame rail), fuel system plumbed. Now working on mocking up the intake and ECM/harness wiring.



Also got a full SC&C suspension front and rear, Z06 disc brakes and working on some rims.

More to come.

[drailed]

Just curious if you have any issues with the S&P headers. I'm leaning towards them on my 67. I had the Edelbrock kit ordered through Pace only to find out 6 weeks later they discontinued all there LS swap stuff, at least for the A bodies.

[CFster]

No problems so far. They fit great. I've got the shorty headers though.

[CFster]

Got it running this week.

http://www.youtube.com/watch?v=5wkT1viszGQ

[gearbanger]

Pretty cool to compare.

http://www.youtube.com/watch?v=3wbuh...eature=related

[CFster]

Been putting a lot of miles on it. Runs like a new car. I'm sorry, but nothing compares to an LS motor.

Next phase is the suspension, rear, brakes and wheels. Should be going in this week.