marcial88 Posted July 3, 2020 Share Posted July 3, 2020 Ok. From all the info I've read and correct me if I'm wrong, I can just remove my 86 2.8l V6 and drop a 3.4l v6 right? And swap the carb in and mechanical fuel pump, sensors and wires from the 2.8l? Plug and play?Has one of you guys done the swap on your 86?1986 Jeep Comanche X4WD GM 2.8L V6Front: Stock Dana 30Rear: Stock AMC 20Los Angeles CASent from my SM-G955U using Tapatalk Link to comment Share on other sites More sharing options...
Eagle Posted July 3, 2020 Share Posted July 3, 2020 1 hour ago, marcial88 said: Ok. From all the info I've read and correct me if I'm wrong, I can just remove my 86 2.8l V6 and drop a 3.4l v6 right? And swap the carb in and mechanical fuel pump, sensors and wires from the 2.8l? Plug and play? Has one of you guys done the swap on your 86? 1986 Jeep Comanche X 4WD GM 2.8L V6 Front: Stock Dana 30 Rear: Stock AMC 20 Los Angeles CA Sent from my SM-G955U using Tapatalk No. First: The 2.8L is externally balanced. That means there's a lump of weight on the flywheel or flexplate to help in balancing the rotating mass. The 3.4L is internally balanced -- it doesn't have that lump of weight on the flywheel/flexplate. So you'll need to take your flywheel or flexplate to a shop, have it neutral balanced, and use that on the 3.4L. Your engine is carbureted. The 3.4s are fuel injected. You will either need to adapt your vehicle to run with the FI system, or swap your intake manifold and carburetor onto the 3.4L. There's probably more, but that's what comes immediately to mind. Link to comment Share on other sites More sharing options...
Pete M Posted July 3, 2020 Share Posted July 3, 2020 you can use the bare block/heads from the 3.4 and drop it in using all your current accessories/exhaust and such BUT: -you need to do the aforementioned re-balancing of the flywheel/flexplate or get an S-10 version that comes balanced -and wire in an electric inline fuel pump. the 3.4 block does not have a place to put the mechanical pump Link to comment Share on other sites More sharing options...
marcial88 Posted July 3, 2020 Share Posted July 3, 2020 you can use the bare block/heads from the 3.4 and drop it in using all your current accessories/exhaust and such BUT: -you need to do the aforementioned re-balancing of the flywheel/flexplate or get an S-10 version that comes balanced -and wire in an electric inline fuel pump. the 3.4 block does not have a place to put the mechanical pump I can pretty much buy new or pull a used flywheel from an s10 right?1986 Jeep Comanche X4WD GM 2.8L V6Front: Stock Dana 30Rear: Stock AMC 20Los Angeles CASent from my SM-G955U using Tapatalk Link to comment Share on other sites More sharing options...
Pete M Posted July 3, 2020 Share Posted July 3, 2020 yes. there's a link in my sig that contains the info down in engine swaps. Link to comment Share on other sites More sharing options...
marcial88 Posted July 3, 2020 Share Posted July 3, 2020 yes. there's a link in my sig that contains the info down in engine swaps. Still new here. I don't know how to get to your sig. I'm using the app. I can use the browser too. 1986 Jeep Comanche X4WD GM 2.8L V6Front: Stock Dana 30Rear: Stock AMC 20Los Angeles CASent from my SM-G955U using Tapatalk Link to comment Share on other sites More sharing options...
Pete M Posted July 3, 2020 Share Posted July 3, 2020 it's a link to the master DIY index: Link to comment Share on other sites More sharing options...
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