Ok so i'm figuring out what i'm going to do with my car starting spring and I would like to do a swap to the buick GN engine. I've heard that with the 4.3l you can take the v8 motor mounts and put them in the v6 spots on the k member and it will bolt in. I was wondering if this is the same for the 3.8l or will I have to custom make some motor mounts? If I do the swap i'm going to use the 700r4 tranny and buy the conversion bracket thing from TCI so it will bolt right up. Other then that I was wondering if there is a way to get it to fit with the stock heads and have AC or do you definatly need the Buick Fwd heads? Other than this is there any other things I need to consider with this swap?

Thanks in advance

 

Good choice on the swap! i have never heard about using the 4.3 mounts, but i used the factory lower mounts from a GN. I bolted the engine to the tranny, and rested the engine in. I marked the location of the new mounts and then pulled the engine again. Drilled new holes in the k frame and bolted them on. I also welded the mounts on, but thats not really needed. As for the AC, unfortunatly you have to use the FWD heads to clear. I had AC in my car, but bought an AC delete plate off ebay. GN exhaust manifolds will work, however a custom down pipe will be needed. I reccomend making a two-peice down pipe to make is easier for removal. the biggest challenge will likely be the wiring. I'm still working on mine.

Good luck with the project and keep us posted!

 

I last did a Buick 350, but the motor mounts are the same as the rear wheel drive 3.8 V6.

https://www.thirdgen.org/forums/engi...olds+buick+fyi

I basically did the same method mentioned above for motor mount placement. The Buick mounts are COMPLETELY DIFFERENT than the chevy mounts, don't even bother trying to use them.

Also, if you use the FWD heads (like Pontiac did with the 89 TTA) the easiest to use are from the 88-90 vin code C 3800 from a lesabre or bonneville.

Good luck!!

 

Keep in mind that if you decide to convert to FWD 3.0L heads the compression ratio is different. A GN piston with a TTA head creates (if I remember correct) 9.0:1 instead of 8.0:1. The car will run fine but you need to lower your max boost (losing performance).

As far as motor mounts - why not just use TTA motor mounts? Stockers are available pretty cheap if I remember correct.

What is your performance goal - are you going to mod the engine or leave it stock? Good Luck!!!