Engine swap advice needed

[1981CJ5]

fuel mileage in my '81 Cj5 - 18-20 mpg, is this good?

I currently have a '81 CJ5 with a 258 I6 but would like to get a little more power. Was thinking of upgrading to a 304, are the benefits worth the expense? Are there any tricks I can do to my 258 to give me a little more power?

I know I need to replace the aging and decrepit Carter BBD, but besides that, what can I do?

Also, my CTO only has 3 stems, does anyone know what hooks where? they are currently all plugged.

Thanks, Joel

 

[redrooster]

Bore and stroke the 258. Put on a 4.0L head and a fuel injection kit from www.customefis.com
You'll have a little hot rod on your hands then.

 

[Tug-n-pull]

With the mileage you get do not change any thing! tug

 

[Snitty]

there really is no crank to stroke the 258... but you can bore it and add a 4.0 head... the only way to get increased stroke is to get the crank machined and use custom rods