Xephius's unnoffical LT1 conversion thread.

[ASTROJOE LT1]

Hi all,

I am going to get my LT1 back early next week and am planning on getting it installed ASAP. Can anyone give me a primer on what to expect with the A/C, PS pump, and Alternator? Can I keep my Astro A/C Compressor? Will the accessories all remount? What should I do, I hope to drive the van 1000+ miles in 3 weeks so I need to get her together.

-=John=-

None of your original Astro accessories will mount on the stock Astro brackets. You need to use either the camaro (passenger side) or corvette (driver side) front bracket.The stock Astro AC compressors all have the main hose block to low to mount without making up some new AC lines like I did.

[mikedamech]

Aloha all, I have almost everything dialed in but I have some questions on the wiring. The 95 Caprice had a low oil lite, a change oil light, and a low coolant wires that I don't know where to put or if I need these at all. I am using both the 98 Astro's fuse/relay box and the Caprice one because of the 2 fans and the EMI fuse among others. I'll be so glad to get this running.

[peter]

I suppose if you really wanna, you could install 3 low-draw lamps somewhere to be able to profit from the warning feature of your ECM.
One other thing you could do is look at your dash panel warning lamps. Look for a light that isn't used, usually because you don't have some particular option. If you're anal as I can be, remove the printed section from that/those dashlights and replace it/them with the writing from the donor vehicle dash. Disconnect the OEM circuit from the lapm socket and repower with your surplus wires from the donor ECM. Now THAT would be purdy darn fancy stuff!

I did somewhat the same thing, 'xceptin' that I was lucky enuf to find a "awd" lamp on my truck, even though my awd wasn't the electronically-controlled version (they changed over a yr or two later). Mine lights up when I switch my NP-241 into 4wd.

[mikedamech]

Thanks Peter, all I can say is Wow, You've given me more ideas and your craftsmanship is awesome it looked like a factory AWD light, just kidding.
I have some more questions, I routed all the Power steering lines and came up with one too many. The pressure line leaves the pump to the brake Hydro boost unit, second pressure hose goes from the booster to the steering gear, The power steering cooler line leaves the gear and goes under the radiator support comes out with a 3/8" hose. The Booster has a 3/8" nipple that I ran to the Reservoir and the large hose going from the reservoir to the pump. My question is can I Tee into the 3/8" hose returning to the reservoir?
Is there Spark plug wires for the 95 LT1 that work well with Headers?

[peter]

What was the question again?

I'd have to check to see what the routing is and get back to you. But why do you wanna tee into the OEM circuit?

[mikedamech]

You Know, I now have two return lines going to the reservoir, one from the brake booster and one from the gear. Anyway I tee'ed it and when I start it I guess I'll find out if there is too much volume.

[Xephius]

For plugs, I used these with my headers. They clear with no problem, but I don't know how they will hold up. Very good quality and the plugs are nice.

As for the T in the return hose, I did the same thing. I think it will work ok, if it does have problems I will fabricate a new tank with two return lines. Just as easy to make two of them if I have to. I had to make a custom hose to run from the LT1 power steering pump to the top of the hydro-boost. All the other lines are stock.

I am in the painful process of electric at this point. If you have any wire info you can share I would be eternally grateful.

Update:
Engine in, I figured out all the plumbing, oil and transmission coolers in. Everything is buttoned up save the fuel lines and the electric. WAARRRGGG Electric.... It should be easy, and if I didn't have to work with the Astro harness it probably would be fine. But as it is, I would like to try and interface with it to keep it as stock as possible. I have detailed notes on the hoses and bits I used to plumb everything up. Also lots of pics of the process. Once I have it done I will write it up. If anyone has any questions, drop me a line I will answer if I can.

[mattconrad]

i am def. watching your progress, is there any place on the internet that i can find more pics of your whole van?

[Xephius]

No pictures up yet. I have lots taken but have not posted them up. I will try and get around to starting my final write-up on the LT1 swap tonight. I gave up on trying to build my own harness and interface it with the Astro harness. I opted to have Brendon at LT1Swap.com do the work of making the harness "self contained". Only 3-5 wires are needed to start the motor and they are plainly labeled. With him you basically have Fuel Pump, Batt, Ignition, and brake/neutral switch, maybe one more, but everything else is optional. As a bonus he give you a free basic reprogram on your PCM to disable VATS or emissions (if running off-road.... yea, off-road). All this starting at $300 including return shipping. He does a top notch job on the harnesses, new fuse box, relays, service light and programming port included. Check him out http://www.lt1swap.com Lots of good info even if you are going to try and do it yourself.

More to come...

[Loner62quiet]

I was beginning to think I was alone in the Houston area. The LT1 swap sounds good. I am still in the the planning stage on my V8 swap so your info and completion will help greatly in my planning. live in the Angleton area