Hello, I just bought a 78 kingcab. The body is great but the engine is tired. I read the other posts about a KA engine swap, but not sure if the KA will bolt to my existing stock 4 speed. Do you swap the 240sx gearbox too when you do the engine swap or use the original or something else? Thanks for any info.

The used KA engines I have seen come with the transmission. I wouldnt want the 4spd for that engine.

the best bet is to swap in the tranny from a hardbody that came with the KA

welcome to the forums

Thanks for the feedback - is there any difference between a KA engine/trans sourced from a 240sx versus a hardbody truck? Since I am starting from scratch, should I target a 240sx doaner or a hardbody truck doner, or does it make no difference?

Also - is this a bolt in swap, as far as the motor mounts and crossmembers, or is there some welding/modifying to do?

Finally - regarding not using a 4 speed with the KA engine. I agree, but I neglected to mention that the truck came with an extra 5 speed trans that the previous owner was going to swap in but never got around to doing. The trans is still in the crate from the rebuilder, so I'd like to use it if there is no advantage to using the trans that is mated with the doner KA engine. So I guess my question is, if I have a newly rebuilt 5 speed trans that is presumably the proper style that goes in this truck originally, should I use it or the newer KA mated trans? Sorry if this is a bit convoluted. Thanks again - great forum.

ka24e pickup version = 134hp@ 5600rpm/152lbft @ 4400rpm, press fit piston pins.

ka24e 240sx version = 140hp @ 5600rpm/152lbft @ 4400rpm, floating piston pins.

ka24de Frontier version = 143hp @ 5600rpm/160lbft @ 4400rpm.

ka24de 240sx version = 155hp @ 5600rpm/160lbft @ 4400rpm.

Get whatever one has the lowest miles, best compression, and best price.There is no reason to shy away from any of them as far as I am concerned. Aftermarket parts are available for all versions. I have the "lowest" one in my 4x4 at 134hp, but it can still zoom past 6000rpm like any other ka24, so its not really that bad. Also, the 96-97 ka24e pickup models had metal backed timing chain guides as opposed to the plastic backed guides on earlier ka24e's that can wear through over time.

IDK if the fs5w71c trannys are different externally or not from model to model. Here is what I know about the ratios; the first gear on 4x4 truck models is low at 3.92:1 as opposed to 3.2:1 on 2wd models. Gears 2-5 are also different for the 2wd/4wd models, but 4th gear is always direct drive @ a 1:1 ratio. IDK about the 240sx versions of the fs5w71c trannys, ratio or shifter location wise, other than they are all classified as fs5w71c's.

its typically easier to make sure you get a hardbody donor... the reason is that the 240 donors have different oil pans and typically need the one from the hardbody anyway

the only reason the 240 versions make more power is the intake manifold... depending on what you plan to do to yours... that loos of power in the truck version will likely be made back up with your mods...

i always suggest using a hardbody donor simply because it makes sense to put the truck engine in a truck... overall... either one will require a few mods and fabrications to fit... but the truck one will most likely require less

Oh, yeah. I forgot about the oil pans... Kind of a big deal sometimes.

The cams are different between the trucks and 240's as well. The ka24e is 232/232 for the truck, and like 242/242 for the 240sx, or something similar to that. The ka24de cams are 232/216 for the Frontier, and something moreso (248/240) for the 240. I have never measured these myself, so this is just stuff I have read. The 240 intake manifolds will add power all by themselves over the trucky's, even with the truck cams, but there may very well be be a loss in low end response, but with some more peak powers. On a hot street truck, this might be sought after.
Modified by seang at 11:53 PM 10/3/2009

Thanks again, great info. My donar search begins...

Here is just a few tidbits...

89-90 240sx STOCK cam intake: 240 degrees duration, .409 in valve lift exhaust: 248 degrees duration, .409 in valve lift

90-97 Hardbody STOCK cam intake: 232 degrees duration, .382 in valve lift exhaust: 232 degrees duration, .382 in valve lift

Heres a youtube vid of a 240 intake swapped HB...http://www.youtube.com/watch?v=PT8vsZPV3EE