[Guest]

Hey guys,

I have been thinking for a couple of years about putting a Chevy 350 in my now 4-banger YJ. I have come across an old 340 engine and thought about using it instead. It will bolt right up to my auto tranny and then still use my np231 for now-

I wondering if anyone has done this-- or what you all think.
I work a Dodge/ Chrysle jeep dealership and all the Mopar gurues around here say that this engine is stronger tahn the 360 and would be a viable option!!!???

Let me know your feedback...

Thanks,

Brad

 

[general420]

Don't know anything about how easily it would bolt up, but I would worry greatly about the longevity of your tranny (TF904 I think) behind that motor.

 

[Guest]

I'd use it just because it's cool. I had a 340 in my '70 Challenger (before I dropped in the 440); it would run 6,000 rpm easy - stock. That will change a bit with the '72-'74 models.

BUT....your tranny won't work. The bell pattern is different. You can, however, find a small block Mopar 999 case and put your tail housing, etc. on it.

I'd still do it!!

 

[Olin18]

V8 + D35 =

to put a V8 into a 4 Dinger YJ requirs pretty much a total rebuild. You will probably break your trans, if you can get it to bolt up. The 231 will probably be ok.
But your axels will Not You will need to a least replace the rear.

 

[1696]

The 340 is a high-revving, high HP motor. Not a torque motor. Torque moves trucks, not HP. I'd use a 360 if you want to use MOPAR power.

And yes, I had a 340 in a previous car, a '73 Challenger. After I was done building it, it would run 12.90's on the quarter all day long on street tires, and 11.90's on a set of slicks with a 125HP nitrous shot. It also needed a 3000rpm converter to get moving.

 

[Caver Dave]

Mobdawg took his SBC/TH-350 YJ to URE a few months back hoping to explode the D35...ended up punching a hole in the oil filter & bending a front leaf, but the 35 held. Must have been the "traction bars"

 

[GeeAea]

The 340 (at least the milder versions) came with a TF904. They didn't just produce a 904 for the slant 6. I'm not sure what DC does to detune the 30RH for the 4 banger.

340 came in several flavors. The 72 (I think) had REAL issues with the castings and had a hard time keeping head gaskets on it.

It would be nice to find a "slap-stick shifter" ..they made to Hurst Dual Gate obsolete. I wish my shifter worked like that .