Hello everyone!! Electrician by trade so please excuse any dumb questions!!
I have a 1991 oldsmobile 98 with the 3.8 v6 l27 series 1 ...motor is toast . i purchased a motor that came out of a 98 grand prix 3.8 supercharged v6 I belive its series 3 l67
Will this new motor mount to the trans from the olds ?
should I be looking at motor mount options ?
What other issues should I look forward to lol
Thanks in advance !!!

If its the original 1998 engine, then its a Series 2 L67 supercharged.

In order for this L67 to run correctly, you will need the matching PCM and trans to go with it. A 98 OBD 2 PCM will not work with a 91 OBD1 chassis/trans. WITHOUT rewiring everything from the engine/trans/instrument cluster etc.

What Mike said ^^^^^^^

. . . and that even if it could bolt right in, the 1991 transmission will get quickly ruined by a L67. It has a lot more torque.

Thank you for your input its greatly appreciated .. im finding it hard to find that exact motor and transmission ... the big picture i would like to work on this with my son and drop a v8 rocket motor and convert to rwd idk if its just pipe dreams but I think im better off trying for that instead of reworking a fwd set up

We've had many say they want to do that, but have never had one actually do it and report back with how great it went. Sorry, don't mean to rain on your parade, but this means a lot more work in real life than in the books. It would start with gutting all of the floor from the engine bay to the trunk release.

I had that dream too, convert my 97 Bonneville to RWD. Sadly, from an engineering standpoint, its a nightmare to do.

There'* a saying to projects like this...

I dont take it as rain on my parade i appreciate the honestly and any criticism so I guess my next questions would be, where would you start ? I've removed the seats and carpet so far .
is there anything i should keep away from so I dont ruin the structural integrity of the car?
How much am I going to have to rewire
what engine/ trans/ rear end combo do you recommend
im going to be piecing this together from multiple vehicles /junkyard im assuming since this is a Frankenstein project and im running on a low budget at the moment 😁
thanks in advance
Nicholas

I love the bonneville its a beautiful car and that quote is great im gonna use that lol
what can I say im a glutton for punishment 😀

Get a 96 or newer chassis. This will eliminate most of the headache.
Anything else we recommend on your current chassis would be pure speculation, guesswork, throwing darts at a blank dart board because no one here has backward a OBD2 engine into a OBD1 chassis. We are a 'general' support forum for GM based vehicles. No longer are we 3800 specialist, 4T60-E guru'* etc. I've been on this board for 17 years and have seen many projects. Can't say as I've seen something like this one.