Welcome to the 'Bolt Jay.
Most liely, it is a 235. If you can get the #s by the distributor, that might help us decipher what it is.
On to your question., I'm going to suggest that you check the timing and/or that operation of the advance. I had a similar problem, especially at the lower rpm band, and found that I needed more advance. Also, check for vacuum leaks.
One more thing. You got any pix of them (I want to see them both!).
