Full Size Jeep Network

a repost from the mothership and comments by SC/397 :

Interesting, but a couple points could be argued..
He mentions not having 4 bolt mains but he didn't mention that the AMC 2 bolt mains are massive with 1/2" bolts. Other small blocks use smaller mains and bolts.
And it is easy to answer this question that he has: "Jeep never used the second-gen AMC V-8 and instead sourced a Buick-derived 350ci with a very flat torque curve for 1968 until 1971. We have not yet found a definite answer as to why." It is because AMC didn't own Jeep until 1970.


https://www.fourwheeler.com/how-to/e...3I9OLY2hQtf3Ao

Is it this one? https://www.fourwheeler.com/how-to/engi ... -8-engine/ You posted the link with an ellipsis in the middle instead of the verbatim link.

And on the note of the engine, Kaiser Jeep had already purchased the tooling for the Buick odd-fire in 67 after offering it a couple years earlier in CJ, so it would make sense that they would keep it in the same engine family for the V8. May not be "definitive" but the logic is there.

Regarding the Buick, seems likely that the supply of the AMC 327 as a commodity engine was coming to an end, since AMC introduced the new 290/343 lightweight small block in 1967. Why then the Buick instead of the newer AMC? The 225 does not share a lot with the 350, other than the mount placement and bell pattern. The 225 is actually 3/4 of the Buick 300 V8, with the crank angles adjusted for the 6-cylinder odd-fire design. The bore of the 350 is larger by 50 thou than the 225, so it shares no internal dimensions with the 225. When GM bought back the design and tooling for the 225, they increased the bore by 0.050" and displacement to 231 presumably to align some of the production tooling with the current 350 V8.

I suspect that, with the supply of 327 ending, Jeep shopped around for a commodity engine that they could put in these vehicles that would fit with the size, purpose and payload of the Wagoneer and J-trucks. Maybe the unified bell pattern was a factor, though Jeep already had produced a few different adapters to the TH400. The manual transmissions in these V8 Jeeps already used a custom bell/adapter that's completely different from the CJ, so no great savings there. Likely Buick had a suitable commodity engine, enough surplus production capacity, and gave Kaiser good terms.