- Location
- Rainy side of Washington
I'm reasonably certain you can just run a whole '99 longblock in a '95 without issues. The one thing you'll need to do is drill and tap a 1/8"-27 NPT pipe thread into a boss on the thermostat housing and extend one wire for your temp gauge sending unit, which is a 15 minute project including scraping the gaskets off and installing a new one.So if I understand this correctly, pretty big "if", I should hold onto the head and exhaust manifold for my '95 4.0 as they *should* bolt on to my '99 block.
By doing so I *should* be able to see some modest performance gains on the '99 due to the more freely flowing head and exhaust ports of the earlier version.
Assuming that I am correct so far in my thinking, can anyone forsee any complications from the OBDII system as a result of the head swap?
In fact I have a 98 ZJ longblock in my 91 MJ right now.