- Joined
- Aug 19, 2001
- Messages
- 10,757
- Reaction score
- 583
- Points
- 113
- Location
- So. Calif (SFV)
- Vehicle Year
- 1990
- Make / Model
- Bronco II
- Engine Type
- 2.9 V6
- Engine Size
- 2.9L V6
- Transmission
- Manual
- 2WD / 4WD
- 4WD
- Tire Size
- 35x12.50R15
I have to agree with what's been said above, the 2.9L and 4.0L are more similar than different. Mine's been flawless as for reliability (excepting for extraneous crap like a blown alternator), and it's easily got over 300K on it now (and I'm not particularly nice to it either).
The 4.0L swap would make sense if yours has issues that require a rebuild (low compression, worn cam, bearings, oil burning, etc.), and is what I intend to do with mine, should the 2.9 ever quit. But reliability alone IMO isn't a good reason to swap. Both engines are great in that department if you keep on top of your cooling system maintenance.
1986-1992 is seven model years of production, and so on.
Your point still stands though (however I would question how many similarities a 2001 engine would have with a 1968 engine... Many things will have changed simply due to fuel injection, emissions, and other improvements over the years, meaning things like sensors and other components will be specific to a much narrower set of model years).
The 4.0L swap would make sense if yours has issues that require a rebuild (low compression, worn cam, bearings, oil burning, etc.), and is what I intend to do with mine, should the 2.9 ever quit. But reliability alone IMO isn't a good reason to swap. Both engines are great in that department if you keep on top of your cooling system maintenance.
You're one year off each timeAnother aspect is parts
2.9l was used from 1986 to 1992, 6 years
4.0l OHV was used from 1990-2000, 10 years
302 was used from 1968 to 2001, 33 years
1986-1992 is seven model years of production, and so on.
Your point still stands though (however I would question how many similarities a 2001 engine would have with a 1968 engine... Many things will have changed simply due to fuel injection, emissions, and other improvements over the years, meaning things like sensors and other components will be specific to a much narrower set of model years).