1985 CJ7 with 4.0l engine and Holley Sniper BBD

This project was geared towards ease and compatibility in mind. The tired knocking 4.2l (258cid) was replaced with a more dependable 4.0l rebuilt engine. Original motor mounts, bellhousing, flywheel, and transmission bolted right up without a problem. This was a 1987 Renix engine so I pulled the old Renix intake, installed the old 4.2l intake (slightly modified on dowel holes) and reinstalled the Holley Sniper EFI BBD. It rumbled to life on the first crank.

Mods: I had to grind the intake dowel holes to allow the intake to align properly with the new heads’ ports. I used the old mechanical fan so I had to order a 4.0l water pump from a 1997 wrangler that had a fan mount on the pulley stem. I also used a 1997 4.0l power steering pump mount with belt tensioner because that way I wasn’t depending on a mount that bolted to the intake that was now switched. The old power steering lines hooked right up. I used 1987 4.0l A/C air compressor bypass pulley to get the serpentine belt aligned properly with the alternator. I’m also running the Holley Hyperspark which went in with no problem because the Renix blocks still had the port for a distributer. The hardest thing was figuring out the whole belt angle problem. I could have probably ordered a later year A/C mount to adapt an easier to find bypass pulley but it worked out.

I did this swap instead of a SBC or some other overpowered mill to keep from tearing up drive train components, maintain a semblance of drivability, and the ease of the transplant process. No Novak or Advance adapters needed, just get the engine accesorized how you want and bolt it up.