gen 4 vs gen 5 3sgte?

I've been building up parts for a 3sgte swap into my gt, and the last thing I need is the actual engine.

I've been searching the local jdm importers, and most of the engines they have are gen 5 st246 engines, and they're all in the 800-1000 dollar range. The gen 4 engines are all in the 1200 dollar range.

I know the gen 5 is a center feed manifold, and has a funky exhaust/turbo cast thing. It supposedly makes 260 crank, and has a higher rev limit, but mostly is just a newer engine, so less miles. That aside, what are the actual differences? I've read that the 5th gen has weaker rods or something of the sort, and also that the ecu is junk?

The plan is to put the 3s in mostly stock, while I have my 5s block built up on the side. The motor would be ran at around the 250 range until I pull the bottom end for the 5s block. Then the power goal is around 450.

I figure the minor 'downsides' of the 5th gen I've read about won't really matter after I swap the 5s bottom end in, and go with aftermarket manifolds and a bigger turbo, but I don't know enough about either motor to say which is better or worse for my purpose.

Would the 5th gen work for my goals? Or am I better off getting a 4th gen for a couple hundred more?

Any help on this topic would be great.

Thanks!

Both engines are nearly the same. Only major difference between them are the intake manifold, coils, knock sensor, intercooler, and a few other small things. The blocks, heads, cams, and internals are the same. What makes the 5th gen a pain is the immobilizer in the ECU. But there are guys that have gotten around that or just run an aftermarket ECU.

With the immobilizer i think its the same as in the gen3 170hp 3sge engine.
The easyest way there is to buy an engine with harness and ecu and also the part that tells the immobilizer that it dont have to immobilize all from the same car ro ensure that it realy would work and then just put it al together in the swap. The part that tells the ecu to not immobilize can be spliced in so the ecu thinks everything is ok all the time and you can start the enginge normal as before (so i heard that works for the gen3 3sge engine so i think it could also work in the 5th gen 3sgte if its the same way to immobilize). But for the gen3 3sge its easyer to buy a 175hp ecu because that dosenr have the immobilizer inside but in the 5th gen 3sgte you dont have another chance to get it running only with aftermarket ecu what could alsl be good for you anyways when you later whant to build a 5sgte from it because then you also need an aftermakret ecu.

I personally am going for a Gen5. My reasons are:

1. It's an engine made for 2002-2008 Caldinas, so they are far newer.
2. Centerfeed manifold has always been a better design than sidefeed. Also, the Gen4 intake manifold is completely bolt on, so you can go with that if you wish later on.
3. It has a larger air-to-air intercooler than the Gen4 to support the highest HP rating out of any 3SGTE iirc. (WRC ST205 might have come with 5HP more, but then again it is a car rated by 1990's standards vs 2000's standards which are more stringent)
4. The coils are essentially the same as newer toyota coils (1zz) so there will be absolutely no problems swapping them if they go bad. Plus, they're good coils. Gen4 coils are hard to find and, although 1zz coils fit just fine, they're not the original coils so I don't know if they have anything special that the stock ECU looks for. Otherwise, the same.
5. Cheaper. For some reason these newer engines are cheaper than Gen4. I guess the lack of the huge toyota logo on the intercooler makes it less appealing and correspondingly less demanded.
6. The stock wiring harness comes with EV14 injector connectors, making them plug and play with newer high-performance injectors like Bosch Motorsport or Injector Dynamics.

The stock ECU is not of importance to me. I like running standalones and tuning them myself.