4.0 pushrods
rlitavecz
Jeeper
- Posts
- 141
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- Location
- Merrillville, IN
- Vehicle(s)
- 1973 CJ-5 258 w/7120 head, Comp Cam, Howell TBI, HEI, stock T15 trans, Dana 20 tc, Dana 30 & 44 axles 3.73 gears, Lock Right both ends
I recently upgraded my 73 CJ to a rebuilt AMC 258 i6 / 4.2l with the 4.0 head. I was told to use whtever pushrods I wanted. Bad advice
The original pushrods for 70s AMC 232 i6 and AMC 258 i6 / 4.2l are actually the shortest ones that were used. The result was a lot of valve clatter. I checked the preload on the lifters and there was none
I searched various years of Jeep 6 cylinders and found that at least 8 different pushrod lengths had been used. Mine measured 9.596" and are the shortest ones available. I replaced them with a set for a 95 Cherokee 4.0. These measured 9.696", .100 longer than my stock ones. The preload on the lifters should be .050"-.070". Napa sells several lengths and they only cost about $3 each. Hope this info helps anyone doing a head swap
The original pushrods for 70s AMC 232 i6 and AMC 258 i6 / 4.2l are actually the shortest ones that were used. The result was a lot of valve clatter. I checked the preload on the lifters and there was none I searched various years of Jeep 6 cylinders and found that at least 8 different pushrod lengths had been used. Mine measured 9.596" and are the shortest ones available. I replaced them with a set for a 95 Cherokee 4.0. These measured 9.696", .100 longer than my stock ones. The preload on the lifters should be .050"-.070". Napa sells several lengths and they only cost about $3 each. Hope this info helps anyone doing a head swap