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Discussion Starter · #1 ·
I've a '79 CJ-7 w/258, TH400 and quadtrack. Would like to swap the 258 for a V8, with minimum changes. What will go with the TH400??

 
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Discussion Starter · #2 ·
Jeep came with an optional AMC V-8 with your tranny that year. IMO an AMC V-8 would probably be the easiest, as all the parts are OEM.

Gary
 

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/wwwthreads_images/icons/smile.gif I saw a nice 401 AMC V8 advertised on the Jeep for sale page which would bolt up to that TH400. That would make your Jeep get up and go!/wwwthreads_images/icons/crazy.gif

CJDave
 

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I just went through this for my nephew.
I can tell you right now that you will be better off changing to a small block chevy.
The AMC engines have cast iron rods, and a new set of forged steel rods will cost over $750. If you stay with the cast iron rods, your Horse Power will have to stay under 150, and your rev limit will have to stay under 3000 RPM. (Pretty crappy for a V-8)
Find a TH-400 case with a chevy bolt pattern, and swap the transmissions out, and put a small block chevy in the jeep. There are several companies that make motor mounts and headers for just this swap, and we found headers for under $125. Motor mounts for $65.
AMC engines have a multitude of problems, including no 4 bolt main blocks, thin head castings, shifted sand casted blocks, cam and valve train problems, all AMC parts are premium prices, and about a dozen serious problems I haven't mentioned here.
Just get the local transmission shop to rebuild your trans in a chevy case, and have at it with a small block.
Almost all Chevy pickup trucks have 4 bolt main blocks.
Good luck, Aaron.

 

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no way...go get a 360 out of a junkyard and bolt that sucker right in in less than a weekend. uner 150 hp??!?!? there are many many pro mud boggers around here that are running400 hp out of AMC 360 and 401...i ran a 350 hp 360 for years in my 76 cj-7 with a th400 and the only thin i ever did was stretch about 4 x-fer case chains in that quadratrac....i now have a 360hp 304....i have never blown an AMC engine (well a 258)(ok i hydrolocked a 304 once too) but that is in 11 years....and i am NOT easy on them!
alsoAMC 360 running from a junkyard...usually about $500....cost for a 350, new th400, and x-fer case?????? and it won't bolt in
just an opinion

 

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/wwwthreads_images/icons/tongue.gif Our '79 CJ7 TH400 Quadra-Trac is apart right now, and I THINK the TH400 has double bolt patterns on it for both the 258 and the 304. Anyway, it has a SLEW of unused holes. Maybe a V8 bolts right to your tranny as it is? Like I mentioned, there was a 401 advertised in Tacotown not too long ago. (That's Salinas CA for you outa state folks) I KNOW the AMCs have a slew of shortcomings, and the oiling system was designed by a two-year old, but they DO run. You CAN go the the grocery store with one in your Jeep./wwwthreads_images/icons/crazy.gif

CJDave
 
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