'67 GTO LS3 Swap

[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