Ok...
I just got through rebuilding a 1996 4.0 in situ that had a broken piston and a very badly cracked head. I was short on time and I needed it running by today. Anyway, I couldn't find a correct year 4.0 in the yards around here, so I decided to grab a head and pistons from a 92 HO. I bought a set of E234k piston rings from RockAuto, which happened to fit the ones I had pulled, but not the originals from the 96. Weird. Apparently the later 4.0's used e925x piston rings, which are 1 - metric and 2 - much smaller. The earlier pistons are MUCH more solidly built, heavier, and they are a direct bolt in on any 4.0. There were a few very minor differences in the head (studs in place of bolts, CTS in back of head...)
Somewhat to my surprise it cranked right up.
Anyway what oil do you recommend for breaking in an engine well? I hope to get another 247xxx miles out of this rebuild
.
I just got through rebuilding a 1996 4.0 in situ that had a broken piston and a very badly cracked head. I was short on time and I needed it running by today. Anyway, I couldn't find a correct year 4.0 in the yards around here, so I decided to grab a head and pistons from a 92 HO. I bought a set of E234k piston rings from RockAuto, which happened to fit the ones I had pulled, but not the originals from the 96. Weird. Apparently the later 4.0's used e925x piston rings, which are 1 - metric and 2 - much smaller. The earlier pistons are MUCH more solidly built, heavier, and they are a direct bolt in on any 4.0. There were a few very minor differences in the head (studs in place of bolts, CTS in back of head...)
Somewhat to my surprise it cranked right up.
Anyway what oil do you recommend for breaking in an engine well? I hope to get another 247xxx miles out of this rebuild
.
