RONS 84 720 Posted January 14, 2023 Report Share Posted January 14, 2023 Has anyone ever put a 5speed from a 84 king cab 2wd behind a automatic engine from a 84 king cab st 2wd? Quote Link to comment
datzenmike Posted January 14, 2023 Report Share Posted January 14, 2023 I'm sure that's been done, yes. You'll need a flywheel preferably from a Z24 engine and a matching clutch and pressure plate. A set of brake and clutch pedals, a clutch master cylinder, a hard line and a hydraulic flex line to connect it to the slave cylinder that mounts on the transmission. The transmission may come with this, if not you's need it possible a clutch arm, dust boot, release collar that matches the pressure plate and release bearing. Depends if the transmission comes with this or if you are removing from another truck. Get everything. you currently have a 3.90 differential and the transmission has a speedometer pinion gear for a 3.545 so the speedometer will be reading way faster than you are going. I don't think the automatic sleeve fits the standard transmissions. The L3N71B automatic is 31.5" long but the manual transmission could be 26" so you need to measure this and if so, the driveshaft will need to be lengthened. The 'automatic engine' will have a six hole spacer plate clipped onto the crankshaft that is there to align the automatic's torque converter. It's not needed and won't allow the flywheel to fit on. In addition an 'automatic engine' will need a pilot bushing tapped into the end of the crankshaft. This helps aligh the transmission and support the front input shaft. Quote Link to comment
DwayneOxford Posted January 15, 2023 Report Share Posted January 15, 2023 Didn't know the auto eng. cranks weren/t drilled for pilot Quote Link to comment
NC85ST Posted January 15, 2023 Report Share Posted January 15, 2023 Mike didn’t say that the crank was not drilled for a pilot bushing, but that you needed to install a pilot bushing in the automatic crank and it should be replaced anytime you replace the clutch as well. Mike outlined it perfectly. I made this swap years ago in my ‘85 and the one thing that stumped me to begin with was that crank spacer, not enough lighting to see it. Buying a parts truck made it easy. 1 Quote Link to comment
Bleach Posted January 15, 2023 Report Share Posted January 15, 2023 I did this on a 620 L18. It should be pretty easy on the 720 2wd. Quote Link to comment
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