Tronman:

Thanks! I read online that GM used an offset bolt pattern unique to these trucks with the rear bolts closer than the front. Just pulled the carb and actually measured the bolt spacing - which I should have done before! The back is spaced the same as the front. Just goes to show:

1. The simple answer is most often right;
2. You can’t believe everything you read on the internet; and
3. I can be a dope - especially when I’m in a hurry!🤪

Thanks again!