AMC 304 Tanny

[YJwonderboy]

Woot! I'm thinking of putting an AMC 304 in my my YJ, out of an old CJ (or maybe a javlelin...who knows), but I don't like the idea of having a 3 speed transmission, just because of the gas mileage. I know the the V8's gonna get really bad gas mileage anyway, but keep in mind, even WITH the V8, it's gonna be a daily driver, so I'm looking for allt he gas mileage I can get, so a three speed transmission just isn't gonna cut it. Does anybody know of any adapters made for the 304 that will adapt a four or five speed to this motor?

[Beat98TJ]

Woot! I'm thinking of putting an AMC 304 in my my YJ, out of an old CJ (or maybe a javlelin...who knows), but I don't like the idea of having a 3 speed transmission, just because of the gas mileage. I know the the V8's gonna get really bad gas mileage anyway, but keep in mind, even WITH the V8, it's gonna be a daily driver, so I'm looking for allt he gas mileage I can get, so a three speed transmission just isn't gonna cut it. Does anybody know of any adapters made for the 304 that will adapt a four or five speed to this motor?

Anything you can put behind a 4.0 or 4.2 will bolt up. A t5 will not hold up but you may want to try a nv3550 5spd. Look on the Novak or Advance Adapters sites for addition information.

[YJwonderboy]

Didn't the 4.2 come with a peugeot? The AX15 would be really good, as it's a medium/heavy duty transmission (It's technically a medium duty, but they hold up better than a LOT of transmissions in its category), I may have ot look in to the nv3550. Thanks for the info, you rock!

[Beat98TJ]

Didn't the 4.2 come with a peugeot? The AX15 would be really good, as it's a medium/heavy duty transmission (It's technically a medium duty, but they hold up better than a LOT of transmissions in its category), I may have ot look in to the nv3550. Thanks for the info, you rock!

The 4.2 in a CJ came with a bunch of tranny options T4, T5, T18, SR4?, etc. and the pugeot in the YJ. An AX15 is a decent tranny behind a 4.0L, but the torque of a 304 would likely hurt it. The 3550 is a better choice.

[YJwonderboy]

O.O I have a question on this motor swap. The NV3550 sounds like the way to go. Now the 304 is a larger motor, so how much work would I have to put into placement of things? Is the 304 a short enough block that i can drop it in without having to move the transmission back, and shortening the driveshaft, because from what i've read, the NP231J T-case will bolt to it, making it seems rather ideal

[YJwonderboy]

Ok, I've looked, and i've looked, but can't find an adapter. I was thinking about the T5 transmission. It's said they are a light duty transmission....but is it still a decently strong tranny?

[Beat98TJ]

Ok, I've looked, and i've looked, but can't find an adapter. I was thinking about the T5 transmission. It's said they are a light duty transmission....but is it still a decently strong tranny?

I would not put a stock Jeep t5 behind a v8. If you upgrade third gear and go thru it it will hold for a while. (Using the world class t5 parts)


I once shattered third in a CJ7 with a stock 258 with a quick shift.

[YJwonderboy]

You were only running a 258? Wow! This is proving difficult...but who said a motor swap was gonna be easy. I WANT A 5-SPEED!! AND I WON'T SETTLE FOR ANYTHING LESS.


anybody got any opinions?