304 Swap to I6 or v6

I did a search, but didn’t get all the answers I was looking for. I have a chance to pick up a 75 CJ5 on the cheap, I was told the 304 needs work to get running. I have an extra 16 and V6 that could be installed.

My question, what would be the easier swap considering motor mounts, bellhousing and other? What would need to be replaced for each engine (I6) (V6) to work in a CJ5 that was set up for a 304? Thanks in advance for your help.

 

The bellhousing will work, I think the passenger side motor mount will need to be changed, as well as exhaust. Personally I would rather put some work(cash) into the V8. I like the straight six, I have one, but would rather have the 8. Never have too much power :twisted: However with gas prices it would be more economical with a 6.
Just my $.02
High5 :stout:

 

To start, the bellhousing pattern of the AMC I6s after 1971 (232, 242, 258) are the same as the V8s (290,304,343,360,390,401). If your I6 is a 258 and has a flywheel, it'll bolt up the same as the 304. The only difference I can thin of would be the pilot tip diameter on the T15 v. the T14 the 258 would usually be paired with. T15s were paired with 258s in the wagons and trucks, so the proper pilot bushing should be available.

V8s are shorter than I6s, so the bellhousing length for the T15 v. the T14 might be different to position the shifter in the same place. If so, it might be easiest to find a T14 from an I6 CJ and use that. Not sure how Jeep accomodated the length difference between the engines.

IMO the V6 (225?) would involve way more work than an AMC I6.

<edit> Just in case you didn't know, the 304 came with the T15 transmission before 1976, and the I6s came with the T14.

 

High 5, if I do buy I will check the 8 and see what it needs, but for now just checking out my options.

Tim, I was thinking the V6 would be more work, plus the I6 is a natural for the 75. Good info!

Did they stop making the 304 after 75 or were they paired with automatics? I thought they stopped making 304 in 79, I could be wrong.

 

The 304 with a T176 went until '81 or '82 ... www.jeeptech.com would have the exact year. After 1975, 3-speed 304s had the T150. Never were any automatics in CJ-5s, only in CJ-7s, CJ-8s and the Wranglers.

 

If you are serious about downgrading the motor to a 6 I am quite sure that you could find someone willing to swap all of their brackets and such straight-across.