70 Lemans Sport

Hi everybody, this is my first post. I have a 70 GTO with a very tired 455 that I took out. It is my first car. I would like to put a LS2 in it. Who makes a good conversion kit? Can I use the original 4 speed or go completely modern? Any input and info would be great. Thanks Steve

67Skylark

Let's see some pictures! should be a great project. Do some reading and you'll find lots of options. I don't have any experience with it, but I would take a hard look at the new Holley stuff. My build was done before the kits were available.

968ls1

iTrader: (8)

Holley just finished their mounts and exhaust and is the only way to go. Search for the A-body thread in the conversions and hybrids section. Their parts fix the typical problems of driveshaft angle and ground clearance for the exhaust.

Project GatTagO

iTrader: (7)

Use the new Holley A-body swap components and yes, you can use a Muncie behind the LS, here is how:

https://ls1tech.com/forums/conversio...-ls-motor.html

Andrew

70 Lemans Sport

Hi, will my 455 flywheel bolt up to the LS2 crank? I went to the Holley site and the A body conversion looks to be made by Hooker. Is that correct? Thanks Steve

Project GatTagO

iTrader: (7)

Read the link that I posted. Hooker is owned by Holley.

Andrew

Jimbo1367

I doubt it. Even if it did, it would be unlikely it would be the same balance.

Just buy one.

70 Lemans Sport

Hey guys, I went to my GM dealership today about a motor. I can get a new crate LS3 motor for a real good price. What harness will I need for the following that is in my car.
1) factory in dash rally gauges with tach
2) heater
3) radio
no AC
4) M21 tranny


I have no idea what to get or where to get it. Any help would be great. Thank you guys for the help so far. Steve

tuske427

iTrader: (1)

I'm sure there are many choices out there, but one way to go is through Speartech. I've used them twice to modify two different harnesses and had great service both times.

https://www.speartech.com/

I've also used a painless wiring harness in one car and that worked well, too.

http://www.painlessperformance.com/

Now, these get your engine running. Has nothing to do with your 1-3. Make sure you get a manual trans harness and it'll include the wire fro hooking up a reverse light. Perhaps someone else can chime in if this reverse wire will work with a M21. I do not have experience with this.

RE: your call outs

1- Your 1970 factory gauge wiring isn't compatible stock with the LS engine. You can have your gauges rebuilt with modern internals from a company like Redline gauge works. They will look the same and work like new. I had mine done there for my '67 Firebird rally gauges and I had great service. I worked with Shannon and my gauges all work great now with my LS engine.

http://redlinegaugeworks.com/


Note: You don't need this for your fuel gauge to work. this is separate and reads off the sender inside your tank. you'd need this for a tach, volts, etc.

2 & 3- you shouldn't have to modify your car for these at all. an LS engine harness is separate from the car's main wiring harness.

I would recommend though to upgrade your factory harness as an LS engine will have greater electrical loads than your original 40+ year old harness was designed to withstand. Not to mention it's 40+ years old. If you don't, at the least use relays and make a new battery terminal for a strong power supply that you can feed your engine to that bypasses the 1970 Le Mans fuse block.

Hope this helps.

Project GatTagO

iTrader: (7)

GM Performance makes a harness and ECU kit for the LS3. As for the wiring in the rest of the car, if it's in good shape, there is no reason to replace it. My 67 Cougar wiring was in good shape and it works just fine.

Andrew

'87 Monte SS

I'll take that 455 off your hands...lol

Project GatTagO

iTrader: (7)

The OP should read through all this:

https://ls1tech.com/forums/conversio...2-gm-body.html

Andrew

70 Lemans Sport

I have already put a complete new harness in the car by Lectric Limited. The old harness had many breaks in it. I will read thru the LSx into 64-72 GM A-body link. Thanks for helping. Thanks for helping. Steve