Pontiac 350 W 350 Auto Trans
 

Hi Folks
New to this forum so not sure how it works. I have a question / Dumb Idea / not sure what but here go’s.
I am starting a 68 Chevy C20 truck rehab. I have the origional Pontiac 350 & 350 Auto Trans I pulled from my 70 Lemans. It ran perfectly when I pulled it out.
Was thinking about freshening them up and installing in the old Chevy Truck.
Open to any & all thoughts, criticism or suggestions! Thought it might be kinda neat. It’s just sitting out in the garage but don’t want to trash it
Dave
[email protected]

I've seen people replace a 350 Chevy engine in an early 1970s GMC 1/2 ton with a Pontiac 400. I wasn't involved, but I don't think it took a lot of effort. Keep in mind the Pontiac engine is much heavier than the Chevy. I would suggest using an aftermarket aluminum intake to reduce weight. From what I remember, the guy doing the engine swap used the Pontiac frame mounts and welded them to his truck frame. If you're keeping the stock fan blade driven by the water pump, you need to make sure the fan is fairly well centered in the fan shroud. This means you might have to add a spacer between the frame mount and the frame.

If I were doing it, I would set the truck on jack stands and measure the distance from the floor to the center of the Chevy water pump pulley. Once the Pontiac motor is sitting in the frame, I would take the same measurement. That should give you a pretty good idea whether any additional spacing is needed between the Lemans frame mount and the truck frame.

Hope this helps.

Sounds like a fun project! Welcome!

Have you considered just dropping them in as they sit? They might work great for years.

Pontiac parts can be scarce and/or expensive so rebuilding an engine might snowball. For example, something as simple-sounding as a "correct" 350 head gasket can turn into a scavenger hunt.

People on this forum will help you no matter what you decide, which is the value of jumping in here.

That P350 may not rev as high but the bottom end torque will be night & day.

I'm putting a 389 together to install in my 67 Suburban. Planning on using squarebody motor mount stands with mid-seventys Pontiac motor mounts. I also want to find a drivers side battery tray to put the battery closer to the starter.

Here are some threads that might help you.

http://forums.maxperformanceinc.com/...d.php?t=596830

https://forums.maxperformanceinc.com...ht=Curious+gmc

https://67-72chevytrucks.com/vboard/...d.php?t=821492

http://67-72chevytrucks.com/vboard/s...d.php?t=458227

I have a 72 400 in my 67 GMC It was pretty easy to install.

I used 73-87 truck frame mounts with the clam shells and the original steel mounts off the Catalina it came from.

https://i.postimg.cc/Kk3CzJwT/67-GMC-2022-1-29.jpg