v6 to 6.0 Liter Vortec Swap

[GioSS]

This is my first post to this forum. I have been busy the last few years working and learning on Harleys, I am now ready to go to town on a car. I would like to swap out from an 85 Cutlass supreme its 3.8v6 and put a 6 Liter Vortec from a pickup, I was doing some research on this site but there isnt much on a modern Vortec swap, saw some people squableing over a 4.3L vortec swap and some 350 Vortec talk, but I want to completely transplant the Motor and transmission, and put a posi rear. I like the idea of having the modern power in an old car. I also plan on putting some air ride in it, and work some of my magic on the car. I have a $9k budget to get the car done (not including paint). I also plan on doing most of the work myself in my garage (with a little help from my friends). Any advice, or if someone has done a similar swap, I would love to hear from you. Also, I was thinking before I put the motor in perhaps putting a cam and freshening it up, so any ideas there would be great also. I have been told that it should fit with the SBC mounts, would the transmission fit also? I want to make the car a sleeper, and with a 6.0 I think it would definately get up and go, the 5.3 in my silverado is effin crazy strong, with the intake, exhaust and bully dog its just bananas. 😀

Thanks for getting back to me...
Gio SS

 

[seawolf18]

You going carbed or fuel injected? Fuel injected you should have a junk yard pull out with the harness, computer, and trans if you want a modern trans. If the 6.0 is low miles, you can just throw a cam in it. You will also need the computer tuned to work with your set up. You will also need swap plates that bolt on the engine so you can use gen 1 clam shell motor mounts. You will also need to swap the frame mounts. use a set or a 80's Monte SS. For headers, a lot of guys use pacesetter 98-02 f-body headers. Some slight mods may have to be done to get them to work. A lot of info about swap info can also be found on ls1tech.com in the hybrids section. There is a very large LSX swap into a g-body thread on there. If your going carbed, its a lot easier. Would would need a carb friendly cam, intake, carb, and a MSD 6010 box to run the ignition system. There is also a good carb section on ls1tech.

 

[tetomas]

You will also need an oil pan and pickup assembly to fit the g-body frame. There are a few out there now that will fit with no frame modification, or you can use the F body pan and notch the crossmember for pan clearance. Also if you plan to run AC you will have to notch the crossmember again, or get a high mount compressor kit and a Sanden compressor. I used the Holley adapter plates, and G body clamshells, just set it in where the space was good and re-drilled the crossmember for the lower mounts to sit on, only had to drill one hole, the rest lined up with factory holes. Must be close I was able to re-use my driveshaft at the stock length. There is also an interferance problem with the number 8 ignition coil and the ac box, I cut the box and re-formed it to make room for the coil. The accessory drive on the truck engine may be too tall to get the hood shut, most people are using F-body accessories or aftermarket stuff. If you go with a different trans. you will also need to build or buy a trans. crossmember, I have a 4L60E, and I just built mine, not as pretty as a factory job but just as strong.

 

[GioSS]

Thanks guys, I am getting the car delivered today. The V-6 is smooth, so I am going to do the Airbags and stereo, while I start collecting the parts for the engine build. I was thinking of going with the Fuelly, but also know how impatient I am so perhaps just carb it. I will definitely be reaching back out to you guys once I research this a little more. If it turns out to be too much work I may just go with a 350 and call it a day. We shall see.