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Transmission Questions

Hey all, New here.
I have a 1995 Saturn Sl1 with a 5speed. I blew a hole in the transmission. Yea. Don't ask, I was having fun. Anyways. I've been reading and want to be sure:
What year s-series are fully bolt in compatible with mine? From the research it seems like 93-97 5speeds attached to the SOHC? DOHC from the Sl2 have different gear ratios? It would still bolt in though correct? And if not what else would I need to swap? I've worked on Subarus so pretty different here! Id appreciate any info you guys can give. Will also be looking for some, If any, modifications I can make to the car..
Thanks!

I don't know personally, but you could call a local salvage yard and ask them what exchanges. They SHOULD have a Hollanders exchange manual that will tell them.

All SOHC MP2 5 spds will bolt up to all SOHC engines.
There were gear ratio changes along the way.
91-93 mid year are the same
93 mid year-94 are the same
95-02 are the same

Stick with 95-02 to have the same gear ratio you had.

As for DOHC MP3s, they will also bolt up to SOHC engines, but of course they have different gear ratios optimized for the torque curve of the DOHC. You can put one on but I don't know how driveable it would be.

Again 95-02 would be what you should stick with.

For 96 and up (OBDII), I know there are codes for incorrect tranny gear ratios. I don't know how the gear ratios are sensed, but if you put a DOHC tranny on an SOHC car, I believe the PCM will be trying to compare the SOHC gear ratio data it has stored to the different gear ratios of the DOHC tranny, which would turn on the SES light, which will fall you in states with emissions testing.

You can swap in an automatic but I don't think you can flash the 95 PCM to match. I believe you have to find a 95 A/T SOHC and it may even have to be from an SL1. 95 was a bizarre year for the S cars PCM wise.

And if you're gonna beat on the 23 yr old ride weld your differential pin so it doesn't punch the case again.

The computer looks at rpm vs. mph to determine gears ratio errors. That is how the upshift arrow works. The dohc transmisions will have lower gears for performance if that is what you are looking for. I don’t have the ratio information but it should be in the repair manuals.

Thanks, Andy.

For the gear ratios, both MP2 (SOHC) and MP3 (DOHC) trannys, see

https://en.wikipedia.org/wiki/Saturn_MP_transmission

Thanks guys for the helps! I've decided i may just buy a lower mileage 95 to replace mine. Ill keep mine for parts and probably slowly rebuild/reseal the engine if parts are readily available.