I just switched my car to 10w30. I'm now running the Quaker State "Defy" oil in 10w30. It's a summer only car and this oil has a good reputation for older motors - it was also on sale so I figured it was worth a shot. It's a synthetic blend.
I tried full synthetic in the engine last year before storage, I don't know why but I didn't like it so much in the old car as I do in my newer cars. I just wasn't "feeling it". Hard to explain what I mean...
I hope one of those trottle bodies works out for you