: Ppl who've done a 307 swap into a 4.1 powered car, need some more help

11-11-04, 12:39 AM
Hi guys,
its been a long time. Things came up in my life and haven't been able to work on the caddy for a long time. To recap, I'm swapping an olds 307 into my 85 brougham coupe. The motor mounts at the beginning were a major problem.

As I sit now, the engine is ready to go into the engine bay (finally!). I took some final measurements though, and I think I've run into a problem. The overall distance from motor mount bracket to the rear of the motor(where the bellhousing bolts up) is only 13 3/8" on the olds, whereas on the 4100 its 17"

Now, I sourced a set of motor mount brackets from an 307 powered brougham, and I'm using a new set of motor mounts for the 4100 motor (as per other posts from earlier(See "Engine swap on 87 Fleetwood" in this same category). According to this post, I have to use a different set of holes in my crossmember to mount up the motor mounts. The post I mentioned above says that it is the forward set of holes on the crossmember. But since the distance between mount and end of motor is shorter on the olds than the 4100, doesnt this mean that I have to use the set of holes in the crossmemeber thats closer to the rear of the car to compensate? I seem to remember trying to put the mounts on the set of holes closer to the rear of the car though, and the holes in the motor mounts don't line up with the holes in the crossmember. Does that mean I have to drill the mounts to get it to work?

I'm at a loss, and I'd really like to get this engine in the car this weekend (time is becoming an issue again)


barge master
11-11-04, 05:00 AM
It's hard to say what you're up against from a description, but if I was doing the job I'd want the engine and frame brackets from a 307 Caddy. Those frames are somewhat universal, with a variety of holes in the crossmember for different applications. I would tend to think the holes would be in the frame for an Olds engine. If not, I'd drop the engine in with the right brackets bolted on, and tack weld the frame brackets to the frame. Then pull it back out, and weld or bolt the brackets in place. It sounds like a big pain and it is, but these kind of jobs take what they take to do. Good luck.

11-11-04, 07:26 PM
Hey Mogul,

Its been a while, I do remember moving the mounts , but i don't remember in which direction all of the holes were already there I think it was only three bolts holing the mount eventhough the mount has a spot for the fourth hole.
Maybe that could help. The distrbutor will sit close to the main plug on the fire wall, just for reference purposes.

Hope this helps!!!