3s-gte block questions

Ok, here's a question for you guys. I have a 6th gen celica gt that i am building up a 3sgte to drop into. I have practicly been given a 3rd gen block, and I already have my 2nd gen head built up with about $2500 worth of mods and work in it. I'm pretty sure the head will fit the block, but my question is if i should go with the 3rd gen block, or a

2nd gen block and the reason i should do it. I can also get a 2nd gen block from a guy for a little bit cheaper than i can the 3rd gen block. So is there any major mechanical difference between the 2nd gen block and 3rd gen block that would make me want to go with it or stay with the 2nd gen head and block? And would there be any drawbacks from matching the 2nd gen head with the 3rd gen block? I have a balanced and knife-edged crank from a 2nd gen that I want to put in the block(if it will work right in the 3rd gen), and I am going with forged pistons..probably JE pistons and eagle rods.

Another of my concerns is that my current 5sfe stuff..coolant hoses lining up/alternator, power steering, and a/c compressor mounting brackets lining up so the belt runs as it did on my 5sfe, or at least like it would on a 3sgte. From what i've heard..all of those are interchangable between the 3s and 5s engines..and the last thing I want to do is spend money to change out those because of a slight difference between the 2nd gen and 3rd gen blocks, if any.

Yet another concern is the wiring harness from a 2nd gen working on the

3rd gen block, or would i have to go with a wiring harness from a 3rd gen?

also, what is this difference in the coolant passages in the 3rd gen block that is different than the 2nd gen?

IF YOU DON'T WANT TO READ ALL OF THIS STUFF ABOVE, JUST READ THIS: Should I go with a 2nd gen head on a 3rd gen block? or a 2nd gen head on a 2nd gen block? And why?

Thanks in advance guys

Difference between the second and third gen blocks....

3rd has a different oil filter location IIRC The 2nd gen one crams in between the turbo and alternator but it is still perfectly servicable with the right tools. I think the oil->water heat exchanger is different on the 3rd gen too. 3rd gen *some* later blocks had thicker walls to the cyls. If you were pushing BIG power (400+ fly hp) I'd try to find one of the thick walled blocks but you can only do this by x-ray testing and you're only gonna do that if you have a good budget and a few blocks. Below 400hp (some say more) its not worth bothering. IIRC therees a few pushing 500+ on 'thin' walled blocks. 3rd oil and water ways are different but 2nd gen blocks can fit 3rd gen heads no problem (look at the differences in the head gaskets between the st205 and st185). Im not 100% about 2nd gen heads on 3rd gen blocks but its not something ive seen flagged as an issue in many many sessions of trawling the archives. 3rd gen sump is slightly different IIRC but nothing to shout about, both are baffled and perfectly capable. AFAIK everything else is identical. Cant help you with the hose info, never tried a swap. Harness - the block wont change it as the only sensors in the block are the knock sensor (im 99% certain the sensor is the same on both) and maybe the oil level warning light that always goes wrong anyway and most people pull out as they check their levels regularly.

Get over to

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and ask on there to be sure (you can register for a free 60 day trial, then its £20 per year) but prepare to be gently ridiculed for putting the 3sgte in a front wheel drive car :-) Dont take anything personally, we just love our 4wd, and they'll be fine. I'm 'coyoteboy' on there too. Theres some commotions going on there at the moment which means some of the uber-gurus have temporarily left (arguments between staff and members which is all being sorted as we speak) but there should be enough left to answer pretty much any 3sgte question you could ever ask. Cars from stock power to >500hp with all combinations of head/block/turbo you could think of lol.