Engine swap

[UpstateJ1078]

I have a 1978 j10 with the 258 3 speed manual and a dana20 transfercase.......my queston is will a amc 360 (out of a 77 or 78 fsj) bolt up to my exsisting drivetrain......if not what modifications would need to be done to complete this swap...

[Lindel]

No. 1: Welcome!

No. 2: The tranny will bolt up, but you'll need new motor mounts and frame horns for the engine, flywheel and pressure plate, the front valance off a V8 rig to correctly fit the V8 radiator, correct spacer to go between the bellhousing and tranny and the correct input shaft for the tranny. I don't think I forgot anything, someone will be along soon to fill in the gaps.

[UpstateJ1078]

thanks for the info....just bought my first fullsize j10( http://elmira.craigslist.org/cto/1868966437.html ) for 800 bucks! woo hoo.....my next question is my drivetrain stout enough to handle a 360 (315 hp/ 400 ft lbs)...i dont do any kind of extreme offroading just some trails. A good friend of mine is offering me this motor with a COMPLETE rebuild top to bottom with all performance parts for a 1000 bucks....i know he has atleast 2500 in the motor but he wrecked his cj-8 that he had planned to put it in....ive heard nothing but good about the 258's but what a dog!lol....like i said i only have 800 in the truck (plus 100 bucks in fluid changes and a tube for the 35 ground hawg) just tryin to get some kind of ballpark figure on how much more on top of the motor it would cost me to swap....thanks so much for the great info and quick response!

[The PIG Smith]

Also, the fuel line for a 258 enters the engine bay on the passenger side while the V8 enters the engine bay on the drivers side.
Thus, the fuel line is on the wrong side.
A small issue to solve, but yet one headache to overcome.

Like Lindel mentioned, the three manual transmission will be the largest technical issue to solve.
The V8 manual transmission has a much longer input shaft and a long spacer between the bellhousing and the transmission.
While a I6 manual transmission may bolt up, the shifter would be up under the dash.
Jeep used the long input shaft and spacer to keep the shifter in the proper location in cab for V8 applications.

It's been debated a lot here, with no real answers...swap in a V8 for your 258 I6 or swap in a later model 4.0.
There are equal number of pros and cons to each, the 360 V8 or a hot 4.0 I6.
You need to decide what parts you have on hand, what parts you will need to purchase, your skill level, time, budget and your tools/shop.

In my humble option, if you have used 360 of moderate condition and you think it will be a easy HP upgrade, you need to do some more homework.
The cost of the project will not justify the V8 swap.
Now, if you have a fresh mild/hot 360 V8 ready to go...well, this for me would change the scope of the project.

If you intent on owning a V8 powered FSJ, then I would recommend saving your $$$ and buy a factory V8 rig; buy a rusted out FSJ that has a V8 and manual transmission to use as a donor; purchase a V8 transmission for the used 360 you plan to swap in or at the very least consider a TH400 for your 360 and Dana20 transfercase.

[The PIG Smith]

OH...and welcome from Fort Wayne, Indiana.
There is no cure for the madness of FSJ ownership!